This chapter describes the BGP configuration commands.

Use the address family command to enter the IPv4 or VPNv4 address family mode allowing configuration of address-family specific parameters. To leave the address family mode and return to the Configure mode use the exit-address-family command.

This command configures the routing exchange between Provider Edge (PE) and Customer Edge (CE) devices. The BGP sessions between PE routers can carry different types of routes (VPN-IPv4 and IPv4 routes). Address families are used to control the type of BGP session. Configure a BGP address family for each VRF configured on the PE router and a separate address family to carry VPN-IPv4 routes between PE routers. All non VPN BGP neighbors are defined using router mode. All VPN BGP neighbors are defined under its associated address family mode. The BGP process with no address-family specified is the default address-family, where any sessions are configured that either are not associated with a VRF or are used to carry IPv4 routes.

Use the no parameter with this command to disable the address-family configurations.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure BGP aggregate entries.

Aggregates are used to minimize the size of routing tables. Aggregation combines the characteristics of several different routes and advertises a single route.The aggregate-address command creates an aggregate entry in the BGP routing table if any more-specific BGP routes are available in the specified range. Using the summary-only parameter advertises the prefix only, suppressing the more-specific routes to all neighbors. In the following example Router1 will propagate network 172.0.0.0 and suppresses the more specific route 172.10.0.0.

The as-set parameter creates an aggregate entry advertising the path for this route, consisting of all elements contained in all paths being summarized. Use this parameter to reduce the size of path information by listing the AS number only once, even if it was included in multiple paths that were aggregated. The as-set parameter is useful when aggregation of information results in an incomplete path information.

Use the no parameter with this command to disable this function.

By default, aggregate address A.B.C.D/M is disabled

Address Family mode

This command was introduced before OcNOS version 1.3.

Use this command to enable sending summarized routes by a BGP speaker to its peers in the router configuration mode or in the address-family configuration mode. Auto-summary is used by a BGP router to advertise summarized routes to its peers. Auto-summary can be enabled if certain routes have already been advertised: in this case, configuring auto-summary advertises the summarized routes first, then corresponding non-summarized routes are withdrawn. If certain routes have already been advertised, and auto-summary is disabled, non-summarized routes are first advertised, then the corresponding summarized routes are withdrawn from all the connected peers.

Use the no parameter with this command to disable this function.

None

By default, auto-summary is disabled

Address Family mode

This command was introduced before OcNOS version 1.3.

 

Use this command to set the BGP option to perform aggregation only when next-hop matches the specified IP address.

Use the no parameter with this command to disable this functionality.

None

By default, bgp aggregate nexthop check is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to compare the Multi Exit Discriminator (MED) for paths from neighbors in different autonomous systems. Multi Exit Discriminator (MED) is used in best path selection by BGP. MED is compared after BGP attributes weight, local preference, AS-path and origin have been compared and are equal. MED comparison is done only among paths from the same autonomous system (AS). Use bgp always-compare-med command to allow comparison of MEDs from different ASs. The MED parameter is used to select the best path. A path with lower MED is preferred. If the bgp table shows the following and the always-compare-med is enabled:

Route1 is compared to Route2. Route2 is best of the two (lower MED). Next, Route2 is compared to Route3 and Route2 is chosen best path again (lower MED). If always-compare-med was disabled, MED is not taken into account when Route1 and Route2 are compared, because of different ASs and MED is compared for only Route1 and Route3. In this case, Route3 would be the best path. The selected route is also affected by the bgp deterministic-med command. Please see bgp deterministic-med command for details. If this command is used to compare MEDs for all paths, it should be configured on every BGP router in the AS.

Use the no parameter with this command to disallow the comparison.

None

By default, bgp always compare med is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set the number of times the local-AS (Autonomous System) is to be prepended.

Use the no parameter with this command to stop prepending the local AS count.

By default, bgp as local count is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to prevent the router from considering the autonomous system (AS) path length as a factor in the algorithm for choosing a best path route.

Use the no parameter with this command to allow the router to consider the AS path length in choosing a best path route.

None

By default, bgp bestpath as-path ignore is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to relax the “same AS-Path” requirement so any candidate eBGP AS-Path with the same AS-path length might be used for eBGP load-balancing.

Normally eBGP load-balancing requires the candidate routes to be equal-cost paths with identical BGP attributes having the same weight, Local-Pref, AS-Path (both the AS numbers and the AS path length), origin, MED, and different next-hop.

Use the no parameter with this command to return to normal operation.

None

By default, as-path multipath-relax is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to allow comparing of the confederation AS path length. This command specifies that the AS confederation path length must be used when available in the BGP best path decision process. It is effective only when bgp bestpath as-path ignore command has not been used.

Use the no parameter with this command to ignore consideration of AS confederation path length in BGP best path selection.

None

BGP receives routes with identical eBGP paths from eBGP peers and selects the first route received as the best path.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to compare router IDs for identical eBGP paths. When comparing similar routes from peers, the BGP router does not consider the router ID of the routes. By default, it selects the first received route. Use this command to include router ID in the selection process; similar routes are compared and the route with the lowest router ID is selected. The router IS is the highest IP address on the router, with preference given to loopback addresses. Router ID can be manually set by using the bgp router-id command.

Use the no parameter with this command to disable this functionality.

None

BGP receives routes with identical eBGP paths from eBGP peers and selects the first route received as the best path.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to change the default bestpath selection by not comparing an originator-ID for an identical EBGP path.

Use the no parameter with this command to disable this functionality.

None

BGP receives routes with identical eBGP paths from eBGP peers and selects the first route received as the best path.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to specify two MED (Multi Exit Discriminator) attributes, confed and missing-as-worst.

The confed attribute enables MED comparison along paths learned from confederation peers. The MEDs are compared only if there is no external Autonomous System (an AS not within the confederation) in the path. If there is an external autonomous system in the path, the MED comparison is not made. For example in the following paths, the MED is not compared with Route3 as it is not in the confederation. MED is compared for Route1 and Route2 only.

The missing-as-worst attribute to consider a missing MED attribute in a path as having a value of infinity, making the path without a MED value the least desirable path. If missing-as-worst is disabled, the missing MED is assigned the value of 0, making the path with the missing MED attribute the best path.

Use the no parameter with this command to prevent BGP from considering the MED attribute in comparing paths.

Router mode

By default, MED value is zero.

This command was introduced before OcNOS version 1.3.

Use this command to always select a preferred older route even when the bgp bestpath compare-routerid command is configured.

Use the no parameter with this command to disable this functionality.

None

By default, tie-break-on-age is enabled.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure routers as route reflectors. Route reflectors are used when all Interior Border Gateway Protocol (iBGP) speakers are not fully meshed. If the clients are fully meshed the route reflector is not required, use no bgp client-to-client reflection command to disable the client-to-client route reflection.

Use the no parameter with this command to turn off client-to-client reflection.

None

When a router is configured as a route reflector, client-to-client reflection is enabled by default.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure the cluster ID if the BGP cluster has more than one route reflector. A cluster includes route reflectors and its clients. Usually, each cluster is identified by the router ID of its single route reflector but to increase redundancy sometimes a cluster may have more than one route reflector. All router reflectors in such a cluster are then identified by a cluster ID. The bgp cluster-id command is used to configure the 4 byte cluster ID for clusters with more than one route reflectors.

Use the no parameter with this command (without any arguments) to remove a previously configured route reflector cluster ID.

By default, cluster id is set bgp cluster id

Router mode

This command was introduced before OcNOS version 1.3.

The following configuration creates a cluster-id 5 including two route-reflector-clients.

Use this command to specify a BGP confederation identifier.

Use the no parameter with this command to remove a BGP confederation identifier.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure the Autonomous Systems (AS) that belong to a confederation. A confederation allows an AS to be divided into several ASs. The AS is given a confederation identifier. External BGP (eBGP) routers view only the whole confederation as one AS. Each AS is fully meshed within itself and is visible internally to the confederation.

Use the no parameter with this command to remove an autonomous system from the confederation.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

In the following configuration example, the neighbor 172.210.30.2 and 172.210.20.1 have iBGP connection within AS 100, neighbor 173.213.30.1 is a BGP connection with a confederation peer 200 and neighbor 6.6.6.6 has an eBGP connection to external AS 300.

In this configuration, the neighbor 5.5.5.4 has an eBGP connection to confederation 300.

Use this command to set the BGP configuration to the standard type. After setting the configuration to the standard type, use the neighbor send-community command to send out BGP community attributes. The zebos configuration type is the default and requires no specific configuration for sending out BGP standard community and extended community attributes.

For the standard type, the no synchronization command is always shown in the configuration, whereas for the zebos type, this command is the default.

Use the no parameter with this command to remove this configuration.

The default configuration type is: bgp config-type zebos

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to enable BGP route dampening and set various parameters. Route dampening minimizes the instability caused by route flapping. A penalty is added for every flap in a flapping route. As soon as the total penalty reaches the suppress limit the advertisement of the route is suppressed. This penalty is decayed according to the configured half time value. Once the penalty is lower than the reuse limit, the route advertisement is un-suppressed. The dampening information is purged from the router once the penalty becomes less than half of the reuse limit.

Use the no parameter with this command to unset BGP dampening parameters.

The default reachability half-life is 15 minutes.

The default reuse limit is 750.

The default suppress limit is 2000.

The default max-suppress value is 4 times the half-life time, or 60 minutes.

Address Family mode

This command was introduced before OcNOS version 1.3.

Use this command to change the default local preference value.Local preference indicates the preferred path when there are multiple paths to the same destination. The path having a higher preference is preferred. The preference is sent to all routers and access servers in the local autonomous system.

Use the no parameter with this command to revert to the default value for local preference.

By default, local preference value is 100

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to compare the Multi Exit Discriminator (MED) variable when choosing among routes advertised by different peers in the same autonomous system. MED is compared after BGP attributes weight, local preference, AS-path and origin have been compared and are equal.

For a correct comparison result, enable this command on all routers in a local AS. After enabling this command, all paths for the same prefix are grouped together and arranged according to their MED value. Based on this comparison, the best path is then chosen. This command compares MED variable when choosing routes advertised by different peers in the same AS, to compare MED, when choosing routes from neighbors in different ASs use the bgp always-compare-med command.

When the bgp deterministic-med command is enabled, routes from the same AS are grouped together, and the best routes of each group are compared. If the BGP table showed:

BGP would have a group of Route1 and a second group of Route2 and Route3 (the same ASs). The best of each group is compared. Route1 is the best of its group because it is the only route from AS 200. Route1 is compared to the Route2, the best of group AS 400 (the lower MED). Since the two routes are not from the same AS, the MED is not considered in the comparison. The external BGP route is preferred over the internal BGP route, making Route3 the best route; the preferred route would be different if always-compare-med command is enabled (See always-compare-med command).

Use the no parameter with this command to disallow this setting.

None

By default, bgp deterministic med is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enforce the first AS for eBGP routes. This command specifies that any updates received from an external neighbor that do not have the neighbor’s configured Autonomous System (AS) at the beginning of the AS_PATH in the received update must be denied. Enabling this feature adds to the security of the BGP network by not allowing traffic from unauthorized systems.

Using the no parameter with this command to disable this feature.

None

By default, enforce-first-as is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure a BGP router to send 4-octet ASN capabilities. If attempting to change the AS capability from 2 to 4 or 4 to 2, a prompt occurs to remove the VRF configuration (if it exists), and reconfiguration is required, because the route distinguisher (RD) configuration would have been created with the current (2 octet or 4 octet) capability, and must be reconfigured before attempting to change the capability.

While loading from a saved configuration with AS4 capability and BGP VRF configuration, the capability will not be changed because of the above described reason.

Use the no parameter with this command to prevent a BGP router from sending 4-octet ASN capabilities.

None

By default, the bgp extended ASN capability and Four-octet capabilities are disabled.

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to reset a BGP session immediately, if the interface used for BGP connection goes down.

Use the no parameter with this command to disable this feature.

None

By default, fast-external failover is enabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable BGP graceful-restart capabilities. The restart-time parameter is used for setting the maximum time that a graceful-restart neighbor waits to come back up after a restart. This value is applied to all neighbors unless you explicitly override it by configuring the corresponding value on the neighbor. The stalepath-time parameter is used to set the maximum time to preserve stale paths from a gracefully restarted neighbor. All stalepaths, unless reinstated by the neighbor after a re-establishment, will be deleted at the expiration of this timer.

Use the no parameter with this command to restore the router to its default state.

By default, the maximum time for neighbors to restart is 90 seconds.

By default, the maximum time to retain stale paths from restarting neighbors is 360 seconds.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to gracefully shut down all BGP IPv4 sessions under this router. The BGP graceful shutdown feature reduces packet loss during maintenance activity.

Use the no parameter with this command to bring up all the sessions under this router after completion of maintenance activity using the bgp g-shut command.

None

By default, bgp g-shut is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable the graceful shutdown capability at the router level and make available the graceful-shutdown related commands at the router and BGP neighbor levels.

Use the no parameter with this command to disable the graceful shutdown capability on a router.

None

By default, the graceful shutdown capability is disabled at the router level

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to sets the local preference of the router to use during graceful shutdown. The local preference value indicates the preferred path when there are multiple paths to the same destination in a single routing database. The path with a higher preference value is the preferred one. The preferred path is sent to all routers and access servers in the local autonomous system.

Use the no parameter with this command to revert to the default setting.

By default, the local preference value is set to 0

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable logging of status change messages without turning on debug bgp commands. OcNOS has many logging services for neighbor status, including debug bgp fsm and debug bgp events. However, these commands cause system performance degradation. If you need to log neighbor status changes only, IP Infusion Inc. recommends turning off all debug commands and using the bgp log-neighbor-changes command instead. A sample output of the log is:

A sample output of the log for an interface down event is:

This command logs the following events:

Use the no parameter with this command to disable this feature.

None

By default, bgp log neighbor changes is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set the delay time for nexthop address tracking. This command configures the delay interval between routing table walks for nexthop delay tracking, after which BGP does a routing table scan on receiving a nexthop change trigger from NSM. The time period determines how long BGP waits before it walks the full BGP table to determine which prefixes are affected by the nexthop changes, after it receives the trigger from NSM about one or more nexthop changes.

Use the no parameter with this command to reset the timer value to the default value.

By default, nexthop-trigger delay time is 5 seconds

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to enable nexthop address tracking. Nexthop address tracking is an event-driven notification system that monitors the status of routes installed in the Routing Information Base (RIB) and reports nexthop changes that affect internal BGP (iBGP) or external BGP (eBGP) prefixes directly to the BGP process. This improves the overall BGP convergence time, by allowing BGP to respond rapidly to nexthop changes for routes installed in the RIB.

If nexthop tracking is enabled after certain routes are learned, the registration of all nexthops for selected BGP routes is done after the nexthop tracking feature is enabled. If nexthop tracking is disabled, and if there are still some selected BGP routes, BGP de-registers the nexthops of all selected BGP routes from NSM.

Use the no parameter with this command to disable this feature. If the no command is given when nexthop tracking is in the process of execution, an error appears and nexthop tracking is not disabled. However, if the nexthop tracking timer is running at the time of negation, the nexthop tracking timer is stopped, and nexthop tracking is disabled.

None

By default, nexthop address tracking is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to set RFC 1771 compatible path selection.

Use the no parameter with this command to revert this setting.

None

Standard compatible path selection mechanism.

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to set the origin path attribute to “IGP” when the origin is a protocol such as RIP, OSPF, or ISIS as specified in RFC 1771. Otherwise, the origin is always set to “incomplete” which is the industry standard.

Use the no parameter with this command to revert this setting.

None

By default, bgp rfc1771 strict is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to manually configure a fixed router ID as a BGP router identifier. When this command is used to configure a fixed router ID, the current router identifier is overridden and the peers are reset.

Use the no parameter with this command to remove a manually configured fixed router ID.

Once the BGP router-id is elected, it may be re-elected in the following cases:

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure scanning intervals of BGP routers. This interval is the period after which router checks the validity of the routes in its database. To disable BGP scanning, set the scan-time interval to 0 seconds.

Use the no parameter with this command to disable this function.

By default, scan-time interval is 60 seconds.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable or disable suppression/modification of incoming BGP updates to IP RIB/FIB table installation.

In a dedicated route reflector, all the routes it receives may not be required to be stored or only few selected routes need to be stored, because it may not lie in the data path.

Table maps are particularly useful to attain this restriction. Table-map command can be used in two ways:

Use this command in Address Family mode to set the table map rule per an IPv4 or IPv6 family.

Use the no parameter with this command to remove the table-map rule.

All BGP routes will be downloaded to IP RIB

Address Family IPv4 mode, and Address Family IPv6 mode

This command was introduced before OcNOS version 1.3.

The following example shows how to set the table-map command without filter for BGP for all address families.

The following example shows how to set the table-map command with filter for BGP for all address families.

The following example shows how to set the table-map command without filter for BGP for an IPv6 address family.

The following example shows how to set the table-map command with filter for BGP for an IPv6 address family.

Use this command to set the update delay for a graceful-restart capable router. The update-delay value is the maximum time a graceful-restart capable router, which is restarting, will defer route-selection and advertisements to all its graceful-restart capable neighbors. This maximum time starts from the instance the first neighbor attains established state after restart. The restarting router prematurely terminates this timer when end-of-RIB markers are received from all its graceful-restart capable neighbors.

Use the no form of this command to set to the update delay to its default value.

By default, update-delay value is 120 seconds

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to reset a BGP neighbor address.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP session for neighbor with IPv4 address for L2VPN EVPN.

None.

Privileged Exec mode.

This command was introduced in OcNOS version 6.4.2.

Use this command to reset the BGP connection for all peers.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP L2VPN EVPN connection for all the BGP peers.

None.

Privileged Exec mode.

This command was introduced in OcNOS version 6.4.2.

Use this command to reset a BGP connection for all peers in a specified Autonomous System.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the session for neighbors with a specific Autonomous System Number (ASN) for L2VPN EVPN.

None.

Privileged Exec mode.

This command was introduced in OcNOS version 6.4.2.

Use this command to reset BGP route flap dampening information.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP connection for all external peers.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset BGP flap statistics.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP connection for all members of a peer group.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP L2VPN EVPN connection for all members of a BGP peer group.

None.

Privileged Exec mode.

This command was introduced before OcNOS version 6.4.2.

Use this command to reset all BGP statistics.

None

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP connection for all peers.

Privileged Exec mode

This command is introduced in OcNOS version 6.0.0.

Use this command to reset the BGP connection for peer.

 

Privileged Exec mode

This command is introduced in OcNOS version 6.0.0.

Use this command to reset an IPv4 BGP neighbor address.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the VPN Routing/Forwarding (VRF) instance for a peer address.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP connection for vrf peer.

Privileged Exec mode

This command is introduced in OcNOS version 6.0.0

Use this command to apply the modified table map or route map rules to the BGP routes in the existing IP routing table.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to reset the BGP connection for vrf peer.

Privileged Exec mode

This command is introduced in OcNOS version 6.0.0

Use this command to enable all BGP troubleshooting functions. Use this command without any parameters to turn on normal bgp debug information.

Use the no parameter with this command to disable this function.

Privileged Exec mode and Configure Mode

This command was introduced before OcNOS version 1.3.

Use this command to set BGP administrative distances. The administrative distance rates the trustworthiness of a routing information source. A higher distance value means a lower trust rating. For example, an administrative distance of 255 means that the routing information source cannot be trusted and should be ignored.

Use the no form of this command to restore the default value (110).

Router BGP mode

None

This command was introduced in OcNOS version 6.0.0.

Use this command to exit Address-Family-vrf, Address-Family-vpnv4 mode.

For information on how to enter the address family mode (IPv4, VPNv4), see address-family.

None

No default value is specified

Address Family-vrf and Address Family-vpnv4 mode.

This command was introduced before OcNOS version 1.3.

The following examples shows the change in the prompt after using this command.

Use this command to define a BGP Autonomous System (AS) path access list. A named community list is a filter based on regular expressions. If the regular expression matches the specified string representing the AS path of the route, then the permit or deny condition applies. Use this command to define the BGP access list globally; use the neighbor router configuration command to apply a specific access list.

Use the no parameter with this command to disable use of the access list.

No default value is specified

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to specify a standard community list (1 to 99) that specifies BGP community attributes.

Use the no parameter with this command to delete the community list entry.

By default, ip community list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to specify an expanded community list (100 to 500) that specifies BGP community attributes.

Use the no parameter with this command to delete the community list entry.

By default, ip community list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use the community-lists to specify BGP community attributes. The community attribute is used for implementing policy routing. It is an optional, transitive attribute and facilitates transfer of local policies through different autonomous systems. It includes community values that are 32-bits long.

There are two kinds of community-lists: expanded and standard. The standard community-list defines the community attributes in a specified format and not with regular expressions. The expanded community-list defines the community attributes with regular expressions.Use the no parameter with this command to delete the community list entry.

By default, ip community list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use the community-lists to specify BGP community attributes. The community attribute is used for implementing policy routing. It is an optional, transitive attribute and facilitates transfer of local policies through different autonomous systems. It includes community values that are 32-bits long. There are two kinds of community-lists: expanded and standard. The standard community-list defines the community attributes in a specified format without regular expressions. The expanded community-list defines the community attributes with regular expressions.

Use this command to add a standard community-list entry. The standard community-list is compiled into binary format and is directly compared with the BGP communities attribute in the BGP updates. The comparison is faster than the expanded community-list. Any community value that does not match the standard community value is automatically treated as expanded.

Use the no parameter with this command to delete the standard community-list entry.

By default, ip community list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use the community-list commands to specify BGP community attributes. The community attribute is used for implementing policy routing. It is an optional, transitive attribute and facilitates transfer of local policies through different autonomous systems. There are two kinds of community-lists: the expanded and standard. The standard community-list defines the community attributes in a specified format and not with regular expressions. The expanded community-list defines the community attributes with regular expressions.

Use the no parameter with this command to delete the community list entry.

By default, ip community list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to create an entry for a standard extended community list.

Use the no parameter with this command to delete the community-list entry.

By default, ip extcommunity list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to create an extended community list.

Use the no parameter with this command to delete the community-list entry.

By default, ip extcommunity list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to create an expanded community list.

Use the no parameter with this command to delete the expanded community-list entry.

By default, ip extcommunity list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to create and delete a standard extended-community list. The extended community attribute is 8 bytes in 2 formats. The sub-type can be route target (rt) or site of origin (soo). Thus, the sub-type of each community must be specified when creating the extended community list. Regarding the formats, an extended community is based on a 6-byte value. These 6-bytes are represented in 4-btye:2-byte format, and may be entered in one of the following forms:

Use the no parameter with this command to delete the extended-community-list entry.

By default, ip extcommunity list is disabled

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to configure the unnumbered peer with all the neighbor configs applicable in L2VPN EVPN address family.

Use the exit parameter with this command to leave L2VPN unnumbered mode.

None

No default value is specified

Address-family IPv4 Unicast Mode

This command was introduced in OcNOS-OTN version 4.2.

Use this command to apply policies based on the route source of which the BGP TCP/IP session formed using an IPv4 address in the update message.

Use the no parameter with this command to disable this function.

By default, import bgp route is disabled

Route-map mode

This command was introduced before OcNOS version 1.3.

Use this command to match the large community.

By default send-community large is enabled for peer

Route-map mode

This command was introduced in OcNOS version 6.1.0.

Use this command to set the number of equal-cost multi-path (ECMP) routes for eBGP or iBGP. You can install multiple BGP paths to the same destination to balance the load on the forwarding path.

Use the no parameter with this command to disable this feature.

Available for the IPv4 and IPv6 unicast addresses.

Address Family mode

This command was introduced before OcNOS version 1.3.

The following example configures 7 routes for ECMP for iBGP.

Use this command to enable the exchange of specific address family routes with a neighboring router. After a TCP connection is opened with a neighboring router, use this command to enable or disable the exchange of address family information. To enable the exchange of multicast and VPNv4 address prefix types, activate neighbors using this command in address family mode.

Use the no parameter with this command to disable exchange of information with a neighbor.

For L2VPN-unnumbered mode:

By default activate is disabled. For all address-families, use this command to enable a neighbor to exchange routing information of a specific address-family with a neighbor.

Address Family mode and l2vpn-unnumbered mode

This command was introduced before OcNOS version 1.3.

Use this command to set a minimum interval between the sending of BGP routing updates. To reduce the flapping of routes, set a minimum advertisement interval so that the BGP routing updates are sent only per interval seconds. BGP dampening can also be used to control the effects of flapping routes.

Use the no parameter with this command to set the interval time to default.

For BGP ununbered mode:

By default, neighbor value for ebgp peer is 30 seconds and IBGP peer is 5 seconds

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer this configuration is given in BGP unnumbered-mode.

Use this command to advertise prefixes (routes) even when the source of the prefixes is from the same Autonomous System (AS) number.

Use this command in a scenario where two routers at different locations use the same Autonomous System number and are connected via an ISP. Once prefixes arrive from one branch at the ISP, they are tagged with the customer’s AS number. By default, when the ISP passes the prefixes to the other router, the prefixes are dropped if the other router uses the same AS number. Use this command to advertise the prefixes at the other side. Control the number of times an AS number is advertised by specifying a number.

In a hub and spoke configuration in a VPN, a PE (Provider Edge) router advertises all prefixes containing duplicate AS numbers. Use this command to configure two VRFs on each PE router to receive and advertise prefixes. One of the VRFs receives prefixes with AS numbers from all PE routers and then advertises them to neighboring PE routers. The other VRF receives prefixes with AS numbers from the CE (Customer Edge) router and advertises them to all PE routers in the hub and spoke configuration.

Use the no parameter with this command to remove the configuration.

For unnumbered peer IPv4 unicast mode commands are configured under v4-unnumbered-mode.

For v4-unnumbered mode:

No default value is specified.

This CLI command is available to configure in all Address-family modes (v4-unnumbered mode, IPv4 unicast, IPv6 unicast, IPv4 labeled-unicast, IPv6 labeled-unicast, VPNv4 unicast, VPNv6 unicast, IPv4/IPv6 VRF, L2VPN EVPN)

This command was introduced before OcNOS version 1.3.

For unnumbered peer configs in L2vpn evpn mode are configured under l2vpn-unnumbered-mode.

Use this command to set the minimum interval between sending of AS-origination routing updates.

Use the no parameter with this command to disable this function.

For BGP unnumbered mode:

By default, neighbor as origination interval is 15 seconds

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer this configuration is given in BGP unnumbered-mode.

Use this command to advertise unchanged BGP attributes to the specified neighbor.

Use the no parameter with this command to disable this function.

For unnumbered peer IPv4 unicast mode commands are configured under v4-unnumbered-mode.

For v4-unnumbered mode:

By default, the neighbor attribute-unchanged is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

Use this command to enable message digest5 (MD5) authentication on a TCP connection between two BGP peers. Configuring MD5 authentication between two BGP peers, means that each segment sent on the TCP connection between the peers is verified. MD5 authentication must be configured with the same password on both BGP peers; otherwise, the connection between them will not be established.

Use the no parameter with this command to delete the MD5 authentication.

Not applicable

Router mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to advertise the graceful restart capability to its neighbor. This configuration indicates that the BGP speaker has the ability to preserve its forwarding state for the address family when BGP restarts.

You must first specify a neighbor’s remote-as identification number assigned by the neighbor router.

Use the no parameter with this command to not advertise the graceful restart capability to its neighbor.

By default, the graceful-restart is disabled

Address Family mode

This command was introduced before OcNOS version 1.3.

Use this command to enable Outbound Router Filtering (ORF) and advertise the ORF capability to its neighbors. The ORFs send and receive capabilities to lessen the number of updates exchanged between neighbors. By filtering updates, this option minimizes generating and processing of updates.

The two routers exchange updates to maintain the ORF for each router:

Only an individual router or a peer group can be configured to be in receive or send mode. A peer-group member cannot be configured to be in receive or send mode.

Use the no parameter with this command to disable this function.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

For v4-unnumbered mode:

By default, the orf prefix-list is disabled

Router Address Family (IPv4 unicast, IPv4 multicast, IPv6, v4-unnumbered) mode

This command was introduced before OcNOS version 1.3.

Use this command to include a neighbor already in an established state for conflict resolution when a TCP connection collision is detected. This command is not required for most network deployments, so users should only use this command when required.

Use the no option with this command to turn this feature off.

For BGP unnumbered mode:

By default, neighbor collide is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to disable the exchange of specific address family routes with a neighboring router for peer-group member. After a TCP connection is opened with a neighboring router, use this command to enable or disable the exchange of address family information for peer-group member.

Use the no parameter with this command to inherit the properties of peer-group. i.e., If peer-group is activated in the given address-family, no of this command will activate the peer member as peer-group is activated in address-family..

By default de-activate is disabled for all peer-group members. For all address-families, Use this command to disable a neighbor to exchange routing information of a specific address-family with a neighbor.

Address Family mode

This command is introduced in OcNOS version 6.0.0. This command is applicable only to neighbor which is a member of peer-group.

Use this command to allow a BGP local router to send the default route 0.0.0.0 to a neighbor to use as a default route. This command can be used with standard or extended access lists.

Use the no parameter with this command to send no route as a default.

For v4-unnumbered mode:

By default, neighbor default originate is disabled

Route Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to associate a description with a neighbor. This command helps to identify a neighbor quickly. This command is useful for an ISP that has multiple neighbor relationships.

Use the no parameter with this command to remove the description.

For BGP unnumbered mode:

By default, the neighbor description is disabled

Router mode and Address Family and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to disallow configuration of infinite hold-time. This command enables the local BGP speaker to reject a hold-time of “0” seconds from a peer (during exchange of open messages) or a user (during configuration).

The no form of this command allows the BGP speaker to accept a hold-time of “0” from a peer or during configuration.

For BGP unnumbered mode:

By default, neighbor disallow infinite holdtime is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to filter route updates from a particular BGP neighbor. Use only one distribute list per BGP neighbor.

Use the no parameter with this command to remove an entry.

For v4-unnumbered mode:

By default, neighbor distribute list is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to disable capability negotiation. This command is used to allow compatibility with older BGP versions that have no capability parameters used in open messages between peers.

Use the no parameter with this command to enable capability negotiation.

For BGP unnumbered mode:

By default, capability negotiation is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to accept and try BGP connections to external peers on indirectly connected networks. Multihop is not established if the only route to the multihop peer is a default route. This avoids loop formation.

Use the no parameter with this command to return to the default.

For BGP unnumbered mode:

By default, maximum hop count is 255

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to enforce BGP neighbors to perform multihop.

Use the no parameter with this command to turn off this feature.

For BGP unnumbered mode:

By default, the maximum hop count is 255

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command enable extended optional parameter length for BGP OPEN messages as specified in RFC 9072.

Use the no form of this command to disable extended optional parameter length.

Extended optional parameter length is disabled by default.

BGP router mode

This command was introduced in OcNOS version 6.0.0.

Use this command to enable the BFD for BGP peers.

Use the no form of the command to disable the BFD option for BGP peers.

Bidirectional Forwarding Detection for BGP peers is disabled by default.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set up a BGP filter. This command specifies an access list filter on updates based on the BGP autonomous system paths. Each filter is an access list based on regular expressions.

Use the no parameter with this command to disable this function.

For v4-unnumbered mode:

By default, filter list is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to start a graceful shutdown for the BGP session of the specified BGP neighbor. The BGP session for this neighbor is shut down after the graceful shutdown timer expires.

If there is no alternate path available for traffic to flow prior the actual shutdown of the BGP session, this path is made available for 60 seconds or for configured time after which the path is no longer available and traffic is dropped.

Use the no parameter with this command to bring up the session again for the specified BGP neighbor whose BGP session had been shut down using the neighbor g-shut command.

By default, neighbor g-shut is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure the value of the graceful shutdown timer. After the timer expires, the BGP session initiated for graceful shutdown is shut down.

Use the no parameter with this command to revert to the default setting.

By default, the timer value is set to 60 seconds

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to specify the maximum number of peers that can be configured in the BGP dynamic peer-group.

Use the no parameter with this command to disable this function.

By default, neighbor word limit is disabled

Router mode and Address Family VRF mode

This command was introduced before OcNOS version 1.3.

Use this command to specify an AS (autonomous system) number to use with BGP neighbor.

Use the no parameter with this command to disable this command.

For BGP unnumbered mode:

By default, local-as is disabled.

Router mode and Address Family-vrf mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3. The new version of the command with “no-prepend” and “replace-as“ option

is introduced in OcNOS version 6.4.1.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to set the number of prefixes that can be received from a neighbor.

Use the no parameter with this command to disable this function.

By default, neighbor maximum prefix is disabled

Address Family mode ad v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

Use this command to make the router the next hop for a BGP-speaking neighbor or peer group. This command allows a BGP router to change the nexthop information that is sent to the iBGP peer. The nexthop information is set to the IP address of the interface used to communicate with the neighbor.

Use the no parameter with this command to disable this feature.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

By default, next hop self is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

Use this command to specify an AS (autonomous system) number to use with BGP dynamic peer-group.

Use the no parameter with this command to disable this function.

By default, neighbor optional as is disabled

Router mode and Address Family VRF mode

This command was introduced before OcNOS version 1.3.

Use this command to ignore received capabilities and use locally configured values.

Use the no parameter with this command to disable this function.

For BGP unnumbered mode:

By default, override-capability is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to make a BGP neighbor passive.

Use the no parameter with this command to disable this function.

For BGP unnumbered mode:

By default, neighbor passive is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to add a neighbor to an existing peer group. Neighbors with the same update policies are grouped into peer groups. This facilitates the updates of various policies, such as distribute and filter lists. The peer group is then configured easily with any of the neighbor commands. Any changes made to the peer group affect all members.

See Usage below for when a peer group and a neighbor have conflicting attribute configurations.

To create a peer group, use the neighbor WORD peer-group command, and then use this command to add neighbors to the group.

Use the no parameter with this command to remove a neighbor from a named peer group.

For BGP unnumbered mode:

No default value is specified

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Note: For unnumbered peer we use peergroup key word to bind the unnumbered peer in group.

When a peer group and a peer (neighbor) have conflicting attribute configurations the following rules apply:

These commands control outbound attribute updates:

These commands control inbound attribute updates:

Use this command to create a dynamic peer group.

Use the no parameter with this command to remove a peer group.

No default value is specified

Router mode and Address Family VRF mode.

This command was introduced before OcNOS version 1.3.

Use this command to set the BGP port number of a neighbor.

Use the no parameter with this command to remove a port number from a BGP neighbor.

For BGP unnumbered mode:

By default, neighbor port is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to specify a prefix list for filtering BGP advertisements.

Filtering by prefix list matches the prefixes of routes with those listed in the prefix list. If there is a match, the route is used. An empty prefix list permits all prefixes. If a given prefix does not match any entries of a prefix list, the route is denied access. When multiple entries of a prefix list match a prefix, the entry with the smallest sequence number is considered to be a real match.

The router begins the search at the top of the prefix list, with the sequence number 1. Once a match or deny occurs, the router does not need to go through the rest of the prefix list. For efficiency the most common matches or denies are listed at the top. The neighbor distribute-list command is an alternative to this command and only one of them can be used to filter the same neighbor in any direction.

Use the no parameter with this command to remove an entry.

For v4-unnumbered mode:

By default, neighbor prefix list is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to establish a BGP peering relationship with a customer edge router.

The specified neighbor only exchanges unicast address prefixes, unless the neighbor is also activated using the neighbor activate command, which allows the exchange of other routing information.

Use the no parameter with this command to delete this peering.

For BGP unnumbered mode:

By default, neighbor remote is disabled

Router mode and Address Family-vrf mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3 and updated in OcNOS version 1.3.6.

Use this command to remove the private autonomous system number (ASN) from outbound updates. Private ASNs are not advertised to the Internet. This command is used with external BGP peers only. The router removes the ASNs only if the update includes private ASNs. If the update includes both private and public ASNs, the system treats it as an error.

Use the no parameter with this command to revert to default.

For v4-unnumbered mode:

By default, neighbor remove private AS is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to set a different restart-time than the global restart-time configured using the bgp graceful-restart command.

Use the no parameter with this command to restore the router to its default state.

By default, restart time is 90 seconds

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to apply a route map to incoming or outgoing routes. This command filters updates and modifies attributes. A route map is applied to inbound or outbound updates. Only the routes that pass the route map are sent or accepted in updates.

Use the no parameter with this command to a route map.

For v4-unnumbered mode:

No default value is specified

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

The following example shows the configuration of the route map named rmap2 and then the use of this map name in the neighbor route-map command.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to make the router a BGP route reflector and set a specified neighbor as its client.

Using route reflectors reduces the number of iBGP peers within an AS. An AS can have more than one route reflector. A route reflector treats other route reflectors as other iBGP speakers.

Use the no parameter with this command to indicate that the neighbor is not a client.

No default value is specified

This command is supported in all Address Family modes.

This command was introduced before OcNOS version 1.3.

In the following configuration, Router1 is the route reflector for clients 3.3.3.3 and 2.2.2.2; it also has a non-client peer 6.6.6.6.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

For unnumbered peer, configs in L2vpn EVPN mode are configured under l2vpn-unnumbered-mode.

Use this command to make a neighbor a route server client.

Use the no parameter with this command to remove the configuration of a neighbor as route server client.

For v4-unnumbered mode:

No default value is specified

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to send that a community attribute to a BGP neighbor.

The community attribute groups destinations in a certain community and applies routing decisions according to those communities. On receiving community attributes, the router reannounces them to the neighbor.

By default, both standard and extended community attributes are sent to a neighbor. To explicitly send only the standard or extended community attribute, run the bgp config-type command with the standard parameter before running this command.

Use the no parameter with this command to not announce community attributes to the neighbor. Use the extended and no parameters to remove extended communities. Specifying no other parameter with no removes standard communities only.

See also neighbor send-community in Chapter 3, BGP Virtual Private Network Commands.

Both standard and extended community attributes are sent to a neighbor.

Address Family mode

This command was introduced before OcNOS version 1.3.

Use this command to send that a community attribute to a BGP neighbor.

Use the no parameter with this command to not announce community attributes to the neighbor.

By default send-community large is enabled for peer

Address Family mode

This command was introduced before OcNOS version 6.1.0.

Use this command to terminate active sessions for a specified neighbor and clear all related routing information.

If a peer group is specified, a large number of peering sessions might be terminated. The show ip bgp summary command displays a summary of BGP neighbors and their connections.

Use description option for operators to transmit a short free-form message to describe why a BGP session was shut down.

Use the no parameter with this command to re-enable a neighbor.

Foe BGP unnumbered mode:

By default, neighbor shutdown is disabled.

Router mode and Address Family-vrf mode and BGP unnumbered mode.

This command was introduced before OcNOS version 1.3. The new version of the command with “description” option is introduced in OcNOS version 6.0.0.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to store updates for inbound soft reconfiguration.

Soft-reconfiguration can be used instead of BGP route refresh capability. Using this command enables local storage of all the received routes and their attributes. This requires additional memory. When a soft reset (inbound) is done on this neighbor, the locally stored routes are re-processed according to the inbound policy. The BGP neighbor connection is not affected.

Use the no parameter with this command to disable this function.

For v4-unnumbered mode:

By default, the neighbor soft reconfiguration inbound is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to close the BGP connection if a capability value does not match the remote peer.

Use the no parameter with this command to disable this function.

For BGP unnumbered mode:

By default, strict capability match is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to set the BGP TCP MSS of a neighbor.

Use the no parameter with this command to remove a TCP MSS setting from a BGP neighbor.

For more information, refer to the command reference page for neighbor tcp-mss in the TCP MSS configuration for BGP neighbors section of the OcNOS Key Feature document, Release 6.4.1.

Use this command to set the timers for a specific BGP neighbor.

Use the no parameter with this command to clear the timers for a BGP neighbor.

For BGP unnumbered mode:

By default, keepalive timer value is 30 seconds

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to selectively leak more-specific routes to a particular neighbor.

When the aggregate-address command is used with the summary-only option, the more-specific routes of the aggregate are suppressed to all neighbors. Use the neighbor unsuppress-map command to selectively leak more-specific routes to a particular neighbor.

Use the no parameter with this command to restore the setting to the default level.

For v4-unnumbered mode:

By default, neighbor unsuppress map is disabled

Address Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to allow internal BGP sessions to use any operating interface for TCP connections.

A loopback interface is most commonly used with this command. The use of loopback interface eliminates a dependency and BGP does not have to rely on the availability of a particular interface for making TCP connections.

Use the no parameter with this command to restore the interface assignment to the closest interface.

For BGP unnumbered mode:

By default, neighbor update source is disabled

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to accept only a particular BGP version.

By default, the system uses BGP version 4 and on request dynamically negotiates down to version 2. Using this command disables the router’s version-negotiation capability and forces the router to use only a specified version with the neighbor.

Use the no parameter with this command to use the default version level of a neighbor.

For BGP unnumbered mode:

By default, the system uses BGP version 4 and on request dynamically negotiates down to version 2

Router mode and BGP unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer below configuration is given in BGP unnumbered-mode.

Use this command to specify a weight value, per address-family, for all routes learned from a neighbor.

The route with the highest weight gets preference when the same prefix is learned from more than one peer. Unlike the local-preference attribute, the weight attribute is relevant only to the local router. The weights assigned using the set weight command override the weights assigned using this command.

Use this command in router mode to specify a weight value for all address families. Use this command in address family mode to specify a weight value per IPv4/IPv6/VPNv4/6PE address family,

When the weight is set for a peer group, all members of the peer group get the same weight. This command can also be used to assign a different weight to an individual peer-group member. When an individually-configured weight of a peer-group member is removed, its weight is reset to its peer group’s weight.

Use the no parameter with this command to remove a weight assignment.

For v4-unnumbered mode:

By default, neighbor weight value is 0

Router Address-Family mode and v4-unnumbered mode

This command was introduced before OcNOS version 1.3.

For unnumbered peer, IPv4 unicast mode commands are configured under v4-unnumbered-mode.

Use this command to create a peer group.

Use the no parameter with this command to remove a peer group.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

This example shows how to create a peer group named group1.

Use this command to specify the networks to be advertised by the BGP routing process. A unicast network address without a mask is accepted if it falls into the natural boundary of its class. A class-boundary mask is derived if the address matches its natural class-boundary.

Use the backdoor parameter to specify a backdoor route to a BGP border router that will provide better information about the network. For data to be advertised by BGP, its routing table must include a route to the specified network. This command specifies the networks to be advertised. The network command works if the network being advertised is known to the router.

The backdoor parameter enables a route to be the preferred route even if it has a greater distance. A network that is specified as a backdoor network is dynamically assigned an administrative distance of 200 ensuring that IGP learned routes are preferred. If a backdoor network is not sourced by the local router, the network is learned from the external routers. If the route is learned from eBGP for a backdoor network, the distance is set to 20 or 200.

Use the no form of this command to remove a network route entry.

No default value is specified

Router Address-family mode

This command was introduced before OcNOS version 1.3.

The following example illustrates a Class-A address configured as a network route. The natural Class-A network prefix mask length of 8 is internally derived, that is, 2.0.0.0/8.

Use this command to enable IGP synchronization for BGP static network routes.

Use this no parameter with this command to disable synchronization of BGP static routes.

None

By default, network synchronization is disabled

Address Family mode

This command was introduced before OcNOS version 1.3.

The following example enables IGP synchronization of BGP static network routes in the router configuration mode.

The following example enables IGP synchronization of BGP static network routes in the IPv6 unicast address-family mode.

Use this command to inject routes from one routing process into another. Redistribution is used by routing protocols to advertise routes that are learned by some other means, such as by another routing protocol or by static routes. Since all internal routes are dumped into BGP, careful filtering is applied to make sure that only routes to be advertised reach the internet, not everything. This command allows redistribution by injecting prefixes from one routing protocol into another routing protocol.

Use the no parameter with this command to disable this function.

By default, redistribute is disabled

Address Family mode and Address Family-vrf mode

This command was introduced before OcNOS version 1.3.

The following example shows the configuration of the route-map name rmap1 and then the use of this map name in the redistribute route-map command.

Use this command to enable a BGP-speaker router for graceful restart. This command stops the whole BGP process and makes OcNOS retain the BGP routes and mark them as stale. Receiving BGP speakers, retain and mark as stale all BGP routes received from the restarting speaker for all address families received in the Graceful Restart Capability exchange.

None

By default, bgp graceful is disabled

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to start a BGP process.

Use the no parameter with this command to disable an existing routing process.

No default value is specified

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to set the large community.

By default send-community large is enabled for peer

Route-map mode

This command was introduced in OcNOS version 6.1.0.

Use this command to restart SNMP in Border Gateway Protocol (BGP)

None

No default value is specified

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to enable IGP synchronization of Internal BGP (iBGP) learned routes with the Internal Gateway Protocol (IGP) system in the router configuration mode or in the address-family configuration mode.

Synchronization is used when a BGP router should not advertise routes learned from iBGP neighbors, unless those routes are also present in an IGP (for example, OSPF). Synchronization may be enabled when all the routers in an autonomous system do not speak BGP, and the autonomous system is a transit for other autonomous systems.

The no synchronization command is used when BGP router can advertise routes learned from its iBGP neighbors without waiting for the IGP reachability to be present.

None

No default value is specified

Address Family modes

This command was introduced before OcNOS version 1.3.

The following example enables IGP synchronization of iBGP routes in Router mode.

The following example enables IGP synchronization of iBGP routes in the IPv6-Unicast address family.

Use this command to globally set or reset the keepalive and holdtime values for all the neighbors.

Use the no parameter with this command to reset timers to default value.

By default, keepalive timer value is 30 seconds

By default, holdtime value is 90 seconds

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure the unnumbered peer with all the neighbor configs applicable in IPv4 unicast address family.

Use the exit parameter with this command to leave IPv4 BGP unnumbered mode.

None

No default value is specified

Address-family IPv4 Unicast Mode

This command was introduced in OcNOS-OTN version 4.2.

Use this command to disable BGP debugging options.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to enter the unnumbered mode in router BGP mode allowing configuration of neighbor specific parameters. In this mode we allow creation of unnumbered peer and allow all the neighbor configuration applicable in router BGP mode.

Use no form of this command to exit unnumbered-mode and return to previous mode.

None

Router BGP mode

This command was introduced in OcNOS-OTN version 4.2.