This chapter describes the OSPFv2 commands.

Use this command to enable authentication for an OSPF area. Specifying the area authentication sets the authentication to Type 1 authentication or simple text password authentication (details in RFC 2328). Setting up a Type 1 authentication configures a 64-bit field for that particular network. All packets sent on this network must have this configured value in their OSPF header. This allows only routers that have the same passwords to join the routing domain. Give all routers that are to communicate with each other through OSPF the same authentication password.

Use the ip ospf authentication-key command to specify a simple text password.

Use the ip ospf message-digest-key command to specify an MD5 password.

Use the no parameter to remove the authentication specification for an area.

Null authentication

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to specify a cost for the default summary route sent into a stub or NSSA area. This command provides the metric for the summary default route, generated by the area border router, into the NSSA or stub area. Use this option only on an area border router that is attached to the NSSA or stub area. Refer to the RFC 3101 for information on NSSA.

Use the no form of this command to remove the assigned default-route cost.

By default, route cost is 1

Router mode

This command was introduced before OcNOS version 1.3.

This example sets the default-cost to 10 for area 1.

Use this command to configure a filter to advertise summary routes on an Area Border Router (ABR).

This command suppresses incoming and outgoing summary routes between this area and other areas. You use this command in conjunction with the prefix-list and access-list commands.

Use the no form of this command to remove a filter.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable OSPF routing on the current interface.

Use no form of this command to disable OSPF routing on the current interface.

No default value is specified

Router mode

This command was introduced in OcNOS version 4.2.

Use this command to send and receive OSPF packets with the specified authentication method on the current interface.

Use no form of this command to stop sending and receiving OSPF packets with the specified authentication method on the current interface.

No default value is specified

Router mode

This command was introduced in OcNOS version 4.2.

Use this command to explicitly specify the cost of the link-state metric in a router-LSA.

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

By default, cost is 10.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to turn on the LSA database-filter for a particular interface.

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

Disabled, all outgoing LSAs are flooded to the interface.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to set the interval during which the router waits to receive an OSPF hello packet from the neighbor before declaring the neighbor down. This value is advertised in the router’s hello packets. It must be a multiple of hello-interval and be the same for all routers on a specific network.

 

Use the no parameter with this command to return to the default time. If you have configured this command specifying the IP address of the interface and want to remove the configuration, use the no parameter with the specified IP address (no ip ospf dead-interval A.B.C.D).

No default value is specified.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to enable the BFD option for OSPF neighbors on an interface. Use the no form of the command to disable the BFD option for OSPF neighbors on an interface.

No default value is specified.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to set the router priority to determine the designated router (DR) for the network.

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

By default, priority is 1.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to specify the interval between hello packets.

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

By default, hello interval is 10 seconds.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this attribute to enable the MPLS LDP IGP SYNC on OSPF.

No default value is specified.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this attribute to configure the hold-down timer for which OSPF will wait for LDP to converge and advertises Max cost.

By default, holddown-timer is 70000 seconds.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to set the OSPF network type on the current interface.

Use no form of this command to unset the OSPF network type on the current interface.

No default value is specified

Router mode

This command was introduced in OcNOS version 4.2.

Use this command to suppress sending hello packets on the current interface.

Use no form of this command to unsuppress sending Hello packets on the current interface.

No default value is specified

Router mode

This command was introduced in OcNOS version 4.2.

Use this command to specify the time between link-state advertisement (LSA) retransmissions for adjacencies belonging to the interface.

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

By default, retransmit interval is 5 seconds.

Router mode

This command was introduced in OcNOS version 6.3.0.

This command sets the traffic engineering (TE) metric for an interface.

Use the no parameter with this command to set the traffic engineering metric to its default.

By default, the area interface cost value for an interface is used.

Router mode

This command was introduced in OcNOS version 6.3.0.

Use this command to set an area as a Not-So-Stubby-Area (NSSA). There are no external routes in an OSPF stub area, so you cannot redistribute from another protocol into a stub area. An NSSA allows external routes to be flooded within the area. These routes are then leaked into other areas. However, the external routes from other areas still do not enter the NSSA. You can configure an area to be a stub area or an NSSA, but not both.

This command simplifies administration when connecting a central site using OSPF to a remote site that is using a different routing protocol. You can extend OSPF to cover the remote connection by defining the area between the central router and the remote router as a NSSA.

Use the no form of this command to remove this designation.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to summarize OSPF routes at an area boundary. A single summary route is then advertised to other areas by the Area Border Routers (ABRs). Routing information is condensed at area boundaries and outside the area. If the network numbers in an area are assigned in a way such that they are contiguous, the ABRs can be configured to advertise a summary route that covers all the individual networks within the area that fall into the specified range.

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

Range is advertised by default.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure a sham link between two Provider Edge on MPLS backbone to make them appear as intra-area link.

If it is desired to have OSPF prefer the routes through the MPLS backbone over the routes through the backdoor link, then the routes through the MPLS backbone must be appear to be intra-area routes. To make a route through the backbone appear to be an intra-area route, it is necessary to make it appear as if there is an intra-area link connecting the two PE routers. This is what we refer to as a "sham link.

Use the no parameter with this command to remove a sham link.

Cost: 1

Router mode

 

This command was introduced in OcNOS version 5.0.

 

Use this command to configure the short-cutting mode of an area. An area shortcut enables traffic to go through the non-backbone area with a lower metric whether or not an ABR router is attached to the backbone area.

Use the no form of this command to disable this function.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to define an area as a stub area. There are two stub area router configuration commands: the stub and default-cost commands. In all routers attached to the stub area, configure the area by using the stub option of the area command. For an area border router (ABR) attached to the stub area, use the area default-cost command.

Use the no-summary parameter with this command to define a totally stubby area. Define an area as a totally stubby area when routers in the area do not need to learn about summary LSAs from other areas.

Use the no form of this command to disable this function.

By default, no stub area is defined.

Router mode

This command was introduced before OcNOS version 1.3

Use this command to configure a link between two backbone areas that are physically separated through other non-backbone area.

In OSPF, all non-backbone areas must be connected to a backbone area. If the connection to the backbone is lost, the virtual link repairs the connection. Configure virtual links between any two backbone routers that have an interface to a common non-backbone area. The protocol treats these routers joined by a virtual link as if they were connected by an unnumbered point-to-point network.

Configure the hello-interval to be the same for all routers attached to a common network. A short hello-interval results in the router detecting topological changes faster but also an increase in the routing traffic. The retransmit-interval is the expected round-trip delay between any two routers in a network. Set the value to be greater than the expected round-trip delay to avoid needless retransmissions.

The transmit-delay is the time taken to transmit a link state update packet on the interface. Before transmission, the link state advertisements in the update packet, are incremented by this amount. Set the transmit-delay to be greater than zero. Also, take into account the transmission and propagation delays for the interface. Include the transit area ID and the corresponding virtual link neighbor’s router ID in each virtual link neighbor to properly configure a virtual link.

Use the no parameter with this command to remove a virtual link.

Default intervals:

Dead interval : 40 seconds

Hello interval: 10 seconds

Retransmit interval: 5 seconds

Transmit delay: 1 second

Router mode

This command was introduced before OcNOS version 1.3

The below example shows the differences between with and without encrypted passwords.

Use this command to control how OSPF calculates the default metric for the interface.

Use the no form of this command to assign cost based only on the interface bandwidth.

By default, OSPF calculates the OSPF metric for an interface by dividing the reference bandwidth by the interface bandwidth. The default value for the reference bandwidth is 100Mbps. The auto-cost command is used to differentiate high bandwidth links. For multiple links with high bandwidth, specify a larger reference bandwidth value to differentiate cost on those links.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable Bidirectional Forwarding Detection (BFD) on all interfaces.

Use the no form of this command to disable BFD.

None

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable the CSPF (Constrained Shortest Path First) feature for an OSPFv2 or OSPFv3 instance.

Use the no parameter with this command to disable CSPF functionality for the OSPFv2 or OSPFv3 instance.

None

By default, CSPF functionality for the OSPFv2 or OSPFv3 instance is enabled.

When CSPF is enabled, disable-better-protection option is by default enabled for OSPFv2.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable link-local signaling feature on OSPF router.

Use no parameter to disable link-local signaling feature on OSPF router.

None

By default, capability lls is enabled

Router mode

This command was introduced before OcNOS version 1.3.

 

Use this command to enable opaque-LSAs which are Type 9, 10 and 11 LSAs that deliver information used by external applications.

Use the no form of this command to disable the feature.

None

By default, opaque-LSA is enabled.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to enable traffic engineering feature on OSPF router.

Use no parameter to disable traffic engineering feature on OSPF router.

None

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to apply multi-VRF capability to OSPF process or to decouple the PE router from the VPN backbone.

Use no parameter to deny multi-VRF capability to OSPF process or to avoid decoupling the PE router from the VPN backbone.

None

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

 

Use this command to clear and restart all OSPF routing processes or a given OSPF routing process.

Privileged Exec Mode

This command was introduced before OcNOS version 1.3.

Use this command to restore the method used to calculate summary route costs per RFC.

RFC 1583 specified a method for calculating the metrics for summary routes based on the minimum metric of the component paths available. RFC 2328 specifies a method for calculating metrics based on maximum cost. With this change, it is possible that all of the ABRs in an area might not be upgraded to the new code at the same time. This command addresses this issue and allows the selective disabling of RFC 2328 compatibility.

Use the no parameter with this command to disable RFC 1583 compatibility.

None

By default, OSPF is RFC 2328 compatible

Router mode

This command was introduced before OcNOS version 1.3

Use this command to display information about OSPF BGP link state distribution.

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

None

Privileged Exec mode and Configure mode

This command was introduced in OcNOS version 4.0.

Use this command to specify the debugging options for OSPFv2 Loop-free Alternate path

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

None

Privileged Exec mode and Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to display debugging option for OSPF redistribute 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 display debug logs of OSPF retransmission information.

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

None

Privileged Exec mode and Configure mode

This command was introduced before OcNOS version 1.3

Use this command to specify debugging options for OSPF.

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 log when link-state advertisement (LSA) rate-limiting timers will expire. These messages are logged only when debug ospf lsa generate or debug ospf lsa refresh is enabled

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

None

Privileged Exec mode and Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to specify debugging options for OSPF event troubleshooting. Use this command without parameters to turn on all the options.

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 specify debugging options for OSPF Interface Finite State Machine (IFSM) troubleshooting.

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 specify debugging options for OSPF Link State Advertisements (LSA) troubleshooting.

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 specify debugging options for OSPF Neighbor Finite State Machines (NFSMs).

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

Privileged Exec mode Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to specify debugging options for OSPF NSM 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.

The debug ospf nsm command enables the display of debug information related to NSM.

Use this command to specify debugging options for OSPF packets.

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 display debug information about the interaction between the OSPF process and the Routing Information Base (RIB).

Use no parameter of this command to disable debugging output.

Privileged Exec mode and Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to debug route calculation. Use this command without parameters to turn on all the options.

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 create a default external route into an OSPF routing domain.

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

The system acts like an Autonomous System Boundary Router (ASBR) when you use the default-information originate command to redistribute routes into an OSPF routing domain. An ASBR does not by default generate a default route into the OSPF routing domain.

When you give the default-information originate command, also specify a route-map to avoid a dependency on the default network in the routing table.

Sets the OSPF metric used in creating the default route. The default metric value is 10.

The value used is specific to the protocol. metric-type The external link type associated with the default route advertised into the OSPF routing domain (see RFC 3101).

By default, 2 Sets OSPF External Type 2 metric.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set a default metric for OSPF.

A default metric facilitates redistributing routes with incompatible metrics. If the metrics do not convert, the default metric provides an alternative. Use this command to use the same metric value for all redistributed routes. Use this command in conjunction with the redistribute command.

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

Built-in, automatic metric translations, as appropriate for each routing protocol.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set OSPF 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).

By default, distance for each type of route (intra-, inter-, or external) is 110

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to filter networks in routing updates. This command redistributes other routing protocols into the OSPF routing table.

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

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

The following example shows the distribution of BGP routing updates based on the access list list1 (network 172.10.0.0).

Use this command to enable the database summary list optimization for OSPFv2.

When this feature is enabled, the database exchange process is optimized by removing the LSA from the database summary list for the neighbor, if the LSA instance in database summary list is the same as or less recent than the listed LSA in the database description packet received from the neighbor.

Use the no form of this command to disable database summary list optimization.

None

By default, database summary list optimization for OSPFv2 is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to run multiple OSPF instances on a subnet.

Use the no parameter with this command to disable OSPF multiple-instance support and reset all OSPF instances to the default instance ID.

None

Multiple-instance support is disabled. The default instance ID is 0.

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to enable fast rerouting on all OSPF interfaces.

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

None

By default, fast rerouting is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure remote-lfa on an area in OSPF.

Use the no form of this command remove the remote-lfa configuration.

Router OSPF mode.

This command was introduced before OcNOS version 6.0.0.

Use this command to configure route-map in OSPF for fast-reroute calculation.

Use the no form of this command remove the route-map applied on fast-reroute calculation.

Router ospf mode.

This command was introduced before OcNOS version 6.0.0.

Use this command to set the delay of primary route installation (to avoid micro loop) after a failover.

Use the no form of this command to set the termination hold-on timer to its default value (600 milliseconds).

<100-100000> Hold on interval in milliseconds

600 milliseconds

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set the tie-breaking policy for selecting a fast reroute repair path. You assign a priority to each type of repair path. The tie-breaker value is used to select an LFA FRR route when multiple LFA FRR routes are available for the same primary route.

Use the no form of this command to set the tie-break preference value for a protection type to its default value as shown in Table 1-19.

To set all types of repair paths to their default priorities, do not specify a repair path with the no form of this command.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure a stub host entry belonging to a particular area.

Using this command, you can advertise specific host routes in the router-LSA as stub link. Since stub host belongs to the specified router, specifying cost is not important.

Use the no form of this command to remove the host area configuration.

No host entry is configured

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to send and receive OSPF packets with the specified authentication method on the current interface.

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

No default value is specified

Interface mode

This command was introduced before OcNOS version 1.3.

In this example, interface eth0 is configured to have no authentication. This will override any text or MD5 authentication configured on this interface.

Use this command to specify an OSPF authentication password for neighboring routers.

This command creates a password (key) that is inserted into the OSPF header when OcNOS originates packets. Assign a separate password to each network for different interfaces. All neighboring routers on the same network with the same password exchange OSPF routing data.

The key can be used only when authentication is enabled for an area with the area authentication command.

Simple password authentication allows a password to be configured for each area. Configure the routers in the same routing domain with the same password.

Use the no parameter with this command to remove an OSPF authentication password.

By default, no password used when exchanging OSPF routing data

Interface mode

This command was introduced before OcNOS version 1.3.

In the following example, an authentication key test is created on interface eth0 in area 0. Note that first authentication is enabled for area 0.

Use this command to enable Bidirectional Forwarding Detection (BFD).

Use this command with either the no or disable parameter to disable BFD.

By default, ip ospf bfd is disabled

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to explicitly specify the cost of the link-state metric in a router-LSA.

The interface cost indicates the overhead required to send packets across an interface. This cost is stated in the Router-LSA’s link. The cost is inversely proportional to the bandwidth of an interface. By default, the cost of an interface is calculated based on the bandwidth (108/ bandwidth). Use this command to set the cost manually.

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

By default, the cost of an interface is calculated based on the bandwidth (108/ bandwidth). The default cost value is 10.

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the cost as 10 on interface eth0 for IP address 10.10.10.50.

Use this command to turn on the LSA database-filter for a particular interface.

OSPF floods new LSAs over all interfaces in an area, except the interface on which the LSA arrives. This redundancy ensures robust flooding. However, too much redundancy can waste bandwidth and might lead to excessive link and CPU usage in certain topologies, resulting in destabilizing the network. To avoid this, use this command to block flooding of LSAs over specified interfaces.

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

Disabled, all outgoing LSAs are flooded to the interface.

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to set the interval during which the router waits to receive an OSPF hello packet from the neighbor before declaring the neighbor down. This value is advertised in the router’s hello packets. It must be a multiple of hello-interval and be the same for all routers on a specific network.

Use the no parameter with this command to return to the default time. If you have configured this command specifying the IP address of the interface and want to remove the configuration, use the no parameter with the specified IP address (no ip ospf dead-interval A.B.C.D).

By default, dead interval is 40 seconds

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows configuring dead-interval for 10 seconds on eth0 interface.

Use this command to enable Hello Suppression and LSA Suppression sent on OSPF interface. Enabling demand circuit on one interface enables hello suppression only for that particular interface.

Use the no parameter with this command to disable Hello Suppression and LSA Suppression

None

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows configuring demand-circuit on eth1 interface.

Use this command to completely disable OSPF packet processing on an interface.

This command overrides the network command.

Use the no option with this command to return to the default setting.

None

By default, this feature is disabled

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to prohibit the interface from being used as the next hop in a repair path.

Use the no option with this command to use the interface as the next hop in a repair path.

None

No default value is specified

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to enable flood reduction on an interface. When this command is configured, an LSA sent out on the interface is set with the DNA bit in the LSA age field. The LSA is not refreshed every refresh interval if there is no change in LSA. Only changed LSAs are sent out on the interface

Use the no option with this command to disable flood reduction on an interface.

None

By default, flood reduction on an interface is disabled

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to specify the interval between hello packets.

The hello-interval is advertised in the hello packets. Configure the same hello-interval for all routers on a specific network. A shorter hello interval ensures faster detection of topological changes but results in more routing traffic.

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

By default, hello interval is 10 seconds

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the hello-interval for 3 seconds on interface eth0.

Use this command to enable multi-area adjacency on point-to-point network and other network types. Multi-area adjacency establishes adjacency between the Area Border Routers (ABRs). The interface of the ABR where this command is configured, shall be associated with multiple areas.

Use the no parameter to disable multi-area adjacency on the given interface on point-to-point network.

By default, multi-area adjacency is disabled

Interface mode

This command was introduced before OcNOS version 1.3.

To configure redundant multi-area adjacency configuration with same area in an OSPF instance.

Use this command to register an MD5 key for OSPF authentication.

Use the no parameter with this command to remove an MD5 key.

Message Digest Authentication is cryptographic authentication. A key (password) and key-id are configured on each router. The router uses an algorithm based on the OSPF packet, the key, and the key-id to generate a message digest that is appended to the packet.

Use this command for uninterrupted transitions between passwords. This is helpful for administrators who want to change the OSPF password without disrupting communication. The system begins a rollover process until all the neighbors have adopted the new password. This allows neighboring routers to continue communication while the network administrator is updating them with a new password. The router will stop sending duplicate packets once it detects that all of its neighbors have adopted the new password.

Maintain only one password per interface, removing the old password whenever you add a new one. This prevents the local system from continuing to communicate with the system that is using the old password. Removing the old password also reduces overhead during rollover. All neighboring routers on the same network must have the same password value to enable exchange of OSPF routing data.

By default, MD5 key for OSPF authentication is disabled.

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows OSPF authentication on the interface eth0 when IP address has not been specified.

The following example shows OSPF authentication on the interface eth0 for the IP address 1.1.1.1. (If the interface has two IP addresses assigned-- 1.1.1.1 & 2.2.2.2, OSPF authentication will be enabled only for the IP address 1.1.1.1)

Use this command to set MTU size for OSPF to construct packets based on this value. Whenever OSPF constructs packets, it uses interface MTU size as Maximum IP packet size. This command forces OSPF to use the specified value overriding the actual interface MTU size.

This command does not configure the MTU settings in the kernel. OSPF does not recognize MTU size changes made in the kernel until the MTU size is updated through this command.

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

By default, OSPF uses interface MTU derived from the kernel.

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to configure OSPF so that it does not check the MTU size during DD (Database Description) exchange.

Use the no form of this command to make OSPF check the MTU size during DD exchange.

By default, during the DD exchange process, OSPF checks the MTU size described in DD packets received from its neighbor. If the MTU size does not match the interface MTU, the neighbor adjacency is not established. Using this command makes OSPF ignore this check and allows establishing of adjacency regardless of MTU size in the DD packet.

Interface mode

This command was introduced before OcNOS version 1.3.

Use this command to set the OSPF network type.

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

By default, OSPF network type is broadcast

interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the network to point-to-point type on the eth0 interface.

Use this command to set the router priority to determine the designated router (DR) for the network.

A router with the higher router priority becomes the DR. If the priority is the same for two routers, the router with the higher router ID takes precedence.

Only routers with a nonzero priority value are eligible to become the designated or backup designated router. Configure router priority for broadcast or NBMA networks only and not for point-to-point networks.

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

By default, ip ospf priority is 1

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the OSPF priority value to 3 on the eth0 interface.

Use this command to set the interval after which adjacency is reset if out-of-band re-synchronization has not occurred. The interval period starts from the time a restart signal is received from a neighbor.

Use the no parameter with this command to set the default value (40 seconds).

By default, the re-synchronization timeout is 40 seconds.

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the OSPF re-synchronization timeout value to 65 seconds on the eth0 interface.

Use this command to specify the time between link-state advertisement (LSA) retransmissions for adjacencies belonging to the interface.

After sending an LSA to a neighbor, the router keeps the LSA until it receives an acknowledgement. If the router does not receive an acknowledgement during the retransmit interval, it retransmits the LSA. Set the retransmission interval value conservatively to avoid needless retransmission. The interval should be greater than the expected round-trip delay between two routers.

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

By default, retransmit interval is 5 seconds

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the ospf retransmit interval to 6 seconds on the eth0 interface.

Use this command to set the estimated time it takes to transmit a link-state-update packet on the interface.

The transmit delay value adds a specified time to the age field of an update. If the delay is not added, the time in which the LSA transmits over the link is not considered. This command is especially useful for low speed links. Add transmission and propagation delays when setting the transmit delay value.

Use the no parameter with this command to return to the default value (1 second).

By default, the transmit delay is 1 second

Interface mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the OSPF transmit delay time to 3 seconds on the eth0 interface.

Use this command for the router to send a SYSLOG message when an OSPF neighbor goes up or down.

Use no parameter of this command to stop sending SYSLOG message.

If not specified, brief is the default option.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to limit the number of Database Descriptors (DD) that can be processed concurrently.

This command is useful when a router's performance is affected from simultaneously bringing up several OSPF adjacencies. This command limits the maximum number of DD exchanges that can occur concurrently per OSPF instance, thus allowing for all of the adjacencies to come up.

Use the no option with this command to remove the limit.

By default, max concurrent dd value is 64

Router mode

This command was introduced before OcNOS version 1.3.

The following example set the max-concurrent-dd value to 4.

Use this command to configure the maximum number of OSPF areas.

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

By default, ospf maximum area is 4294967294

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure OSPF routers interconnecting to NBMA (Non-Broadcast Multi-Access) networks. Include one neighbor entry for each known non-broadcast network neighbor. Configure the neighbor address on the primary address of the interface.

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

The default priority is 0 and polling interval is 120 seconds.

Router mode

This command was introduced before OcNOS version 1.3.

This example shows neighbor configured with a priority value and poll interval time.

Use this command to enable OSPF routing with a specified area ID (and optionally an instance ID) on interfaces with IP addresses that match the specified network address.

OSPF routing is enabled per IPv4 subnet basis. You define the network address using the prefix length or a subnet mask.

Use the no parameter with this command to disable OSPF routing on the interfaces.

Network address defined using the prefix length:

Network address defined using subnet mask:

No network area is configured

Router mode

This command was introduced before OcNOS version 1.3.

The following the use of the network command with OSPF multiple-instance support disabled.

The following shows the use of the network command with OSPF multiple-instance support enabled.

Use this command to set an OSPF Area Border Router (ABR) type.

Use the no parameter with this command to revert the ABR type to the default setting (cisco).

Specifying the ABR type allows better functioning in a multi-vendor environment. The ABR types are:

By default, ABR type is Cisco

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to attach the interface to the router OSPF area. When this is enabled, any existing configuration of router ospf attached to the interface is erased.

Use no form of this command to disable. When this is disabled, any existing configuration of interface attached to the router ospf is erased.

None

None

Configure mode

This command was introduced before OcNOS version 4.2.

Use this command to Enable flood reduction on all OSPF interface. When this command is configured, an LSA sent out on the OSPF interface is set with the DNA bit in the LSA age field. If there is no change in LSA, it is not refreshed every refresh interval. LSAs are sent out on the interface only if there is a change in an LSA

Use the no option with this command to disable flood reduction on all OSPF interfaces.

None

By default, flood reduction on all OSPF interfaces is disabled

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to disable RFC 2328 compatibility on point-to-point interfaces.

By default, in a point-to-point network OSPF packets are transmitted using multicast addresses. By disabling point-to-point RFC 2328 compatibility, packets are transmitted using the unicast address of the neighbor.

Use the no parameter with this command to enable RFC 2328 compatibility on point-to-point interfaces.

None

By default, RFC 2328 compatibility is enabled (packets transmitted using multicast addresses).

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to specify a router ID for the OSPF process.

Configure each router with a unique router ID. In an OSPF router process which has active neighbors, a new router ID is used at the next reload or when you start the OSPF manually.

Use the no parameter with this command to force OSPF to use the previous router ID.

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

The following example shows a specified router ID 2.3.4.5.

Use this command to limit the maximum number of LSAs that can be supported by the OSPF instance.

Use the no parameter with this command to have an unlimited number of LSAs.

No default value is specified. unlimited number of LSAs.

Router mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the database overflow to 5 and shutting down in that event.

Use this command to limits the number of AS-external-LSAs a router can receive once it is in the wait state.

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

The default OSPF exit overflow interval is 0 second and number of external LSDB limit is unlimited.

Router mode

This command was introduced before OcNOS version 1.3.

The following example shows setting the maximum number of LSAs to 5 and the time to recover from overflow state to be 3.

Use this command to suppress sending Hello packets on all interfaces or on a specified interface.

This command configures OSPF on simplex Ethernet interfaces. Since a simplex interface represents only one network segment between two devices, configure the transmitting interface as a passive interface. This ensures that OSPF does not send hello packets for the transmitting interface. Both the devices can see each other via the hello packet generated for the receiving interface.

Use the no form with this command to resume sending hello packets on all interfaces, or on a specified interface.

The default OSPF exit overflow interval is 0 second and number of external LSDB limit is 100000.

Router mode

This command was introduced before OcNOS version 1.3.

This command redistributes routes from routing protocols, static routes, and kernel routes into an OSPF routing table.

Use the no form of this command to disable redistribution.

By default, redistribution is disabled.

Router mode

This command was introduced before OcNOS version 1.3.

The following example shows redistributing OSPF instance 2 into OSPF instance 1.

The following example shows redistributing OSPF instance 2 into OSPF instance 1, with an external metric of 10, metric type 1, a route-map named rmp1, and an external route tag of 3.

Use this command to enter router mode and to configure an OSPF routing process.

Specify the process ID to configure multiple instances of OSPF. When running a single instance of OSPF, you do not

need to specify a process ID.

Use the no parameter with this command to terminate an OSPF routing process.

No routing process defined

Configure mode

This command was introduced before OcNOS version 1.3.

This example shows the use of the router ospf command to enter router mode. Note the change in the prompt.

This command displays the information of Graceful Restart capable RSVP client to ISIS or OSPF, CSPF that are currently shutdown.

None

Privileged Exec modes

This command was introduced before OcNOS version 5.0.

Use this command to display the set OSPF debugging option.

None

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

This is a sample output from the show debugging ospf command. Some lines in this output wrap around, they might not wrap around in the actual display.

Use this command to display general information about all OSPF routing processes.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Table 1-19 explains the routing process fields.

Use this command to display the ABRs and ASBRs for OSPF instances.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

This is a sample output from the show ip ospf border-routers command.

Table 1-20 explains the border router fields.

Use this command to display a summary of the OSPF database.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Table 1-21 explains the fields for each database entry.

Use this command to display details of the OSPF database.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

This is sample output with the external and self-originate parameters.

This is sample output with the opaque-as and self-originate parameters.

This is a sample output with the adv-router parameter.

This is sample output with the router and link state ID parameters.

This is sample output using the adv-router parameter for flood reduction.

Table 1-22 explains the fields for each database entry.

Table 1-23 explains the fields for each database entry.

Table 1-24 explains the fields for each database entry.

Type 2 Net Link States (“network” Parameter)

Table 1-25 explains the fields for each database entry.

Type 3 Summary LSAs (“summary” Parameter) and Type 4 ASBR Summary LSAs (“asbr-summary” Parameter)

Table 1-26 explains the fields for each database entry.

Type 5 AS External LSAs (“external” Parameter)

Table 1-27 explains the fields for each database entry.

Type 7 NSSA External Link States (“nssa-external” Parameter)

Table 1-28 explains the fields for each database entry.

 

Use this command to show the IGP shortcut LSP used by OSPF.

None

Exec mode

This command was introduced before OcNOS version 1.3.

Table 1-29 explains the fields in the output.

Use this command to show the IGP shortcut route calculated by OSPF.

Exec mode

This command was introduced before OcNOS version 1.3.

Table 1-30 explains the fields in the output.

Use this command to display interface information for OSPF.

Privileged Exec mode and Exec mode

This command was introduced before OcNOS version 1.3.

Table 1-31 explains the fields for each interface entry.

The following is sample output of this command when DoNotAge is enabled:

The following is sample output of this command when Hello-Suppression is enabled:

Use this command to display multi-area adjacency information for OSPF.

Privileged Exec mode and Exec mode

This command was introduced before OcNOS version 1.3.

The following is a sample output of this command:

Table 1-32 explains the fields for each adjacency entry.

Use this command to display information about OSPF neighbors.

Privileged Exec mode and Exec mode

This command was introduced before OcNOS version 1.3.

Table 1-33 explains the fields for each neighbor entry.

This is sample output from the command when the detail parameter is specified:

Table 1-34 explains the fields for each neighbor detail entry.

This is sample output from the command when the detail parameter is specified and Hello-Suppression is enabled:

Use this command to display the OSPF routing table.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Each entry in this table has a code preceding it indicating the source of the routing entry.

Table 1-35 explains the fields of route codes.

Table 1-36 shows the route entry fields.

The following is a sample output with the process identifier parameter.

Use this command to display sham link information.

Privileged Exec mode and Exec mode

This command was introduced before OcNOS version 5.0.

The following is the display of the sham link information for two routers, one with the sham link up and one with sham link down.

 

 

 

Use this command to display information about opaque LSAs.

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use this command to display virtual link information.

Privileged Exec mode and Exec mode

This command was introduced before OcNOS version 1.3.

The following is the display of the virtual link information for two routers, one with the virtual link up and one with virtual link down.

The following is the display of the virtual link information for two routers, one with the virtual link up and one with virtual link down when flood reduction is enabled

If Hello-Suppression is enabled

Table 1-38 explains the fields for each virtual-links entry.

Use this command to display OSPF process parameters and statistics.

None

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

This is an example of the output from the show ip protocols command:

Table 1-39 explains the fields for each ip protocol entry.

Use this command to display routes with alternate next hops.

None

Privileged Exec mode

This command was introduced before OcNOS version 1.3.

Use the this command to temporarily shut down a protocol in the least disruptive manner and to notify its neighbors that it is going away.

Use the no parameter of this command.

None

No default value is specified

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to configure the SNMP context name which will be mapped to each OSPFv2 instance.

When context name is configured OSPF OID will be registered with SNMP to that context.

Use no form of the command to un-map the SNMP context name from OSPFv2 instance and unregister OSPF OID from SNMP.

Router OSPF mode

This command was introduced before OcNOS version 5.1.

Use this command restart SNMP in OSPF

None

By default, SNMP restart is disabled.

Configure mode

This command was introduced before OcNOS version 1.3.

Use this command to summarize or suppress external routes with the specified address range.

Use the no option with this command to disable summary address.

An address range is a pairing of an address and a mask that is almost the same as IP network number. For example, if the specified address range is 192.168.0.0/255.255.240.0, it matches 192.168.1.0/24, 192.168.4.0/22, 192.168.8.128/25 and so on.

Redistributing routes from other protocols into OSPF requires the router to advertise each route individually in an external LSA. Use this command to advertise one summary route for all redistributed routes covered by a specified network address and mask. This minimizes the size of the OSPF link state database.

By default, tag value is 0

Router mode

This command was introduced before OcNOS version 1.3.

The following example uses the summary-address command to aggregate external LSAs that match the network 172.16.0.0/24 and assign a tag value of 3.

This command sets the traffic engineering (TE) metric for an interface.

The traffic engineering metric is used in OSPF-TE Link State Advertisements. If the traffic engineering metric is not set, the ip ospf cost value for an interface is used in OSPF-TE Link State Advertisements.

Use the no parameter with this command to set the traffic engineering metric to its default.

By default, the ip ospf cost value for an interface is used.

Interface mode

This command was introduced before OcNOS version 1.3.

This command sets the minimum interval to accept the same link-state advertisement (LSA) from OSPF neighbors.

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

By default, Minimum LSA Arrival timer is 1 sec.

Router mode

This command was introduced before OcNOS version 1.3.

Use this command to set the Shortest-Path First (SPF) best-path schedule minimum and maximum delay between receiving a change to SPF calculation in milliseconds.

Use no parameter of this command to unset the SPF best-path schedule.

Default minimum delay: 500 milliseconds

Default maximum delay: 50000 milliseconds (50 seconds)