Additional Paths at the AF Level
Configure R2 to Send All Additional Paths and R3 to Receive all Additional Paths
R2
#configure terminal | Enter the Configure mode. |
(config)#router bgp 100 | Enter BGP router mode |
(config-router)#address-family ipv4 unicast | Configure the address family ipv4 under router BGP |
(config-router-af)#bgp additional-paths send | Configure R2 to send additional paths to all iBGP neighbors |
(config-router-af)#bgp additional-paths select all | Configure R2 to select all available paths to send to all iBGP neighbors |
(config-router-af)#exit-address-family | Exit Address Family mode and return to Router mode. |
(config-router)#exit | Exit the router BGP mode and return to the configure mode |
(config)#commit | Apply commit |
(config)#exit | Exit the configure mode |
R3
#configure terminal | Enter the Configure mode. |
(config)#router bgp 100 | Enter BGP router mode |
(config-router)#address-family ipv4 unicast | Configure the address family ipv4 under router BGP |
(config-router-af)#bgp additional-paths receive | Configure R3 to receive additional paths from all iBGP neighbors |
(config-router-af)#exit-address-family | Exit Address Family mode and return to Router mode. |
(config-router)#exit | Exit the router BGP mode and return to the configure mode |
(config)#commit | Apply commit |
(config)#exit | Exit the configure mode |
Validation
R2
#show ip bgp neighbors 10.1.1.2
BGP neighbor is 10.1.1.2, remote AS 100, local AS 100, internal link
BGP version 4, remote router ID 3.3.3.3
BGP state = Established, up for 00:00:26
Last read 00:00:26, hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
Route refresh: advertised and received (old and new)
Address family IPv4 Unicast: advertised and received
Received 26 messages, 1 notifications, 0 in queue
Sent 27 messages, 1 notifications, 0 in queue
Route refresh request: received 0, sent 0
Minimum time between advertisement runs is 5 seconds
For address family: IPv4 Unicast
BGP table version 17, neighbor version 17
Index 1, Offset 0, Mask 0x2
AF-dependant capabilities:
Add-Path Send Capability : advertised
Add-Path Receive Capability : received
Community attribute sent to this neighbor (both)
1 accepted prefixes
1 announced prefixes
Connections established 3; dropped 2
Local host: 10.1.1.1, Local port: 50428
Foreign host: 10.1.1.2, Foreign port: 179
Nexthop: 10.1.1.1
Nexthop global: ::
Nexthop local: ::
BGP connection: non shared network
Last Reset: 00:00:31, due to BGP Notification received
Notification Error Message: (Cease/Other Configuration Change.)
#show ip bgp
BGP table version is 21, local router ID is 2.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, l - labeled
S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 100.1.1.0/24 11.1.1.2 0 100 0 200 i
* 12.1.1.2 0 100 0 200 i
* 13.1.1.2 0 100 0 200 i
* 14.1.1.2 0 100 0 200 i
*>i 200.1.1.0 21.1.1.2 0 100 0 300 i
Total number of prefixes 2
#show ip bgp 100.1.1.0
BGP routing table entry for 100.1.1.0/24
Paths: (4 available, best #1, table Default-IP-Routing-Table)
Advertised to non peer-group peers:
12.1.1.2 13.1.1.2 14.1.1.2
200
11.1.1.2 from 11.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external, best
rx path_id: -1 tx path_id: 0
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 06:02:02 2017
200
12.1.1.2 from 12.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 1
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 06:02:10 2017
200
13.1.1.2 from 13.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 2
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 06:01:48 2017
200
14.1.1.2 from 14.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 3
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 06:01:51 2017
R3
#show ip bgp neighbors 10.1.1.1
BGP neighbor is 10.1.1.1, remote AS 100, local AS 100, internal link
BGP version 4, remote router ID 2.2.2.2
BGP state = Established, up for 00:00:36
Last read 00:00:36, hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
Route refresh: advertised and received (old and new)
Address family IPv4 Unicast: advertised and received
Received 167 messages, 12 notifications, 0 in queue
Sent 171 messages, 1 notifications, 0 in queue
Route refresh request: received 0, sent 0
Minimum time between advertisement runs is 5 seconds
For address family: IPv4 Unicast
BGP table version 91, neighbor version 91
Index 1, Offset 0, Mask 0x2
AF-dependant capabilities:
Add-Path Send Capability : received
Add-Path Receive Capability : advertised
Community attribute sent to this neighbor (both)
1 accepted prefixes
1 announced prefixes
Connections established 15; dropped 14
Local host: 10.1.1.2, Local port: 179
Foreign host: 10.1.1.1, Foreign port: 50428
Nexthop: 10.1.1.2
Nexthop global: ::
Nexthop local: ::
BGP connection: non shared network
Last Reset: 00:00:36, due to BGP Notification sent
Notification Error Message: (Cease/Other Configuration Change.)
#show ip bgp
BGP table version is 93, local router ID is 3.3.3.3
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, l - labeled
S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i 100.1.1.0/24 11.1.1.2 0 100 0 200 i
* i 14.1.1.2 0 100 0 200 i
* i 13.1.1.2 0 100 0 200 i
* i 12.1.1.2 0 100 0 200 i
*> 200.1.1.0 21.1.1.2 0 100 0 300 i
* 22.1.1.2 0 100 0 300 i
* 23.1.1.2 0 100 0 300 i
* 24.1.1.2 0 100 0 300 i
Total number of prefixes 2
#show ip bgp 100.1.1.0
BGP routing table entry for 100.1.1.0/24
Paths: (4 available, best #1, table Default-IP-Routing-Table)
Advertised to non peer-group peers:
21.1.1.2 22.1.1.2 23.1.1.2 24.1.1.2
200
11.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal, best
rx path_id: 0 tx path_id: 0
Not advertised to any peer
Last update: Fri Jan 6 06:12:52 2017
200
14.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 3 tx path_id: -1
Not advertised to any peer
Last update: Fri Jan 6 06:13:03 2017
200
13.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 2 tx path_id: -1
Not advertised to any peer
Last update: Fri Jan 6 06:13:03 2017
200
12.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 1 tx path_id: -1
Not advertised to any peer
Last update: Fri Jan 6 06:13:03 2017
Configure R2 and R3 to Send and Receive All Additional Paths
R2
#configure terminal | Enter the Configure mode. |
(config)#router bgp 100 | Enter BGP router mode |
(config-router)#address-family ipv4 unicast | Configure the address family ipv4 under router BGP |
(config-router-af)#bgp additional-paths send-receive | Configure R2 to send additional paths to and receive additional paths from all iBGP neighbors |
(config-router-af)#bgp additional-paths select all | Configure R2 to select all available paths to send to all iBGP neighbors |
(config-router)#exit | Exit the router BGP mode and return to the configure mode |
(config)#commit | Apply commit |
(config)#exit | Exit the configure mode |
R3
#configure terminal | Enter the Configure mode. |
(config)#router bgp 100 | Enter BGP router mode |
(config-router)#address-family ipv4 unicast | Configure the address family ipv4 under router BGP |
(config-router-af)#bgp additional-paths send-receive | Configure R3 to send additional paths to and receive additional paths from all iBGP neighbors |
(config-router-af)#bgp additional-paths select all | Configure R3 to select all available paths to send to all iBGP neighbors |
(config-router)#exit | Exit the router BGP mode and return to the configure mode |
(config)#commit | Apply commit |
(config)#exit | Exit the configure mode |
Validation
• Verify that R2 sends all 4 paths to the route 100.1.1.0/24 to R3 and receives all 4 paths to the route 200.1.1.0/24 from R3
• Verify that rx path_ids of all 4 paths to 200.1.1.0/24 received from R3 match the tx path_ids of 200.1.1.0/24 on R3
• Verify that R3 sends all 4 paths to the route 200.1.1.0/24 to R2 and receives all 4 paths to the route 100.1.1.0/24 from R2
• Verify that rx path_ids of all 4 paths to 100.1.1.0/24 received from R3 match the tx path_ids of 100.1.1.0/24 on R3
R2
#show ip bgp neighbors 10.1.1.2
BGP neighbor is 10.1.1.2, remote AS 100, local AS 100, internal link
BGP version 4, remote router ID 3.3.3.3
BGP state = Established, up for 00:09:32
Last read 00:09:32, hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
Route refresh: advertised and received (old and new)
Address family IPv4 Unicast: advertised and received
Received 25 messages, 0 notifications, 0 in queue
Sent 25 messages, 0 notifications, 0 in queue
Route refresh request: received 0, sent 0
Minimum time between advertisement runs is 5 seconds
For address family: IPv4 Unicast
BGP table version 12, neighbor version 12
Index 1, Offset 0, Mask 0x2
AF-dependant capabilities:
Add-Path Send Capability : advertised and received
Add-Path Receive Capability : advertised and received
Community attribute sent to this neighbor (both)
4 accepted prefixes
4 announced prefixes
Connections established 1; dropped 0
Local host: 10.1.1.1, Local port: 179
Foreign host: 10.1.1.2, Foreign port: 51842
Nexthop: 10.1.1.1
Nexthop global: ::
Nexthop local: ::
BGP connection: non shared network
#show ip bgp
BGP table version is 41, local router ID is 2.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, l - labeled
S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 100.1.1.0/24 11.1.1.2 0 100 0 200 i
* 12.1.1.2 0 100 0 200 i
* 13.1.1.2 0 100 0 200 i
* 14.1.1.2 0 100 0 200 i
*>i 200.1.1.0 21.1.1.2 0 100 0 300 i
* i 22.1.1.2 0 100 0 300 i
* i 23.1.1.2 0 100 0 300 i
* i 24.1.1.2 0 100 0 300 i
Total number of prefixes 2
#show ip bgp 100.1.1.0
BGP routing table entry for 100.1.1.0/24
Paths: (4 available, best #1, table Default-IP-Routing-Table)
Advertised to non peer-group peers:
12.1.1.2 13.1.1.2 14.1.1.2
200
11.1.1.2 from 11.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external, best
rx path_id: -1 tx path_id: 0
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 05:36:35 2017
200
12.1.1.2 from 12.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 1
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 05:36:40 2017
200
13.1.1.2 from 13.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 2
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 05:36:43 2017
200
14.1.1.2 from 14.1.1.2 (1.1.1.1)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 3
Advertised to non peer-group peers:
10.1.1.2
Last update: Fri Jan 6 05:36:46 2017
#show ip bgp 200.1.1.0
BGP routing table entry for 200.1.1.0/24
Paths: (4 available, best #1, table Default-IP-Routing-Table)
Advertised to non peer-group peers:
11.1.1.2 12.1.1.2 13.1.1.2 14.1.1.2
300
21.1.1.2 (metric 20) from 10.1.1.2 (3.3.3.3)
Origin IGP, metric 0, localpref 100, valid, internal, best
rx path_id: 0 tx path_id: 0
Not advertised to any peer
Last update: Fri Jan 6 05:40:21 2017
300
22.1.1.2 (metric 20) from 10.1.1.2 (3.3.3.3)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 1 tx path_id: 1
Not advertised to any peer
Last update: Fri Jan 6 05:40:25 2017
300
23.1.1.2 (metric 20) from 10.1.1.2 (3.3.3.3)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 2 tx path_id: 2
Not advertised to any peer
Last update: Fri Jan 6 05:40:29 2017
300
24.1.1.2 (metric 20) from 10.1.1.2 (3.3.3.3)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 3 tx path_id: 3
Not advertised to any peer
Last update: Fri Jan 6 05:40:29 2017
R3
#show ip bgp neighbors 10.1.1.1
BGP neighbor is 10.1.1.1, remote AS 100, local AS 100, internal link
BGP version 4, remote router ID 2.2.2.2
BGP state = Established, up for 00:12:40
Last read 00:12:40, hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
Route refresh: advertised and received (old and new)
Address family IPv4 Unicast: advertised and received
Received 31 messages, 0 notifications, 0 in queue
Sent 31 messages, 0 notifications, 0 in queue
Route refresh request: received 0, sent 0
Minimum time between advertisement runs is 5 seconds
For address family: IPv4 Unicast
BGP table version 17, neighbor version 17
Index 1, Offset 0, Mask 0x2
AF-dependant capabilities:
Add-Path Send Capability : advertised and received
Add-Path Receive Capability : advertised and received
Community attribute sent to this neighbor (both)
4 accepted prefixes
4 announced prefixes
Connections established 1; dropped 0
Local host: 10.1.1.2, Local port: 51842
Foreign host: 10.1.1.1, Foreign port: 179
Nexthop: 10.1.1.2
Nexthop global: ::
Nexthop local: ::
BGP connection: non shared network
#show ip bgp
BGP table version is 42, local router ID is 3.3.3.3
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, l - labeled
S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i 100.1.1.0/24 11.1.1.2 0 100 0 200 i
* i 12.1.1.2 0 100 0 200 i
* i 13.1.1.2 0 100 0 200 i
* i 14.1.1.2 0 100 0 200 i
*> 200.1.1.0 21.1.1.2 0 100 0 300 i
* 22.1.1.2 0 100 0 300 i
* 23.1.1.2 0 100 0 300 i
* 24.1.1.2 0 100 0 300 i
Total number of prefixes 2
#show ip bgp 100.1.1.0
BGP routing table entry for 100.1.1.0/24
Paths: (4 available, best #1, table Default-IP-Routing-Table)
Advertised to non peer-group peers:
21.1.1.2 22.1.1.2 23.1.1.2 24.1.1.2
200
11.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal, best
rx path_id: 0 tx path_id: 0
Not advertised to any peer
Last update: Fri Jan 6 05:36:49 2017
200
12.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 1 tx path_id: 1
Not advertised to any peer
Last update: Fri Jan 6 05:36:53 2017
200
13.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 2 tx path_id: 2
Not advertised to any peer
Last update: Fri Jan 6 05:36:57 2017
200
14.1.1.2 (metric 20) from 10.1.1.1 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal
rx path_id: 3 tx path_id: 3
Not advertised to any peer
Last update: Fri Jan 6 05:37:00 2017
#show ip bgp 200.1.1.0
BGP routing table entry for 200.1.1.0/24
Paths: (4 available, best #1, table Default-IP-Routing-Table)
Advertised to non peer-group peers:
22.1.1.2 23.1.1.2 24.1.1.2
300
21.1.1.2 from 21.1.1.2 (4.4.4.4)
Origin IGP, metric 0, localpref 100, valid, external, best
rx path_id: -1 tx path_id: 0
Advertised to non peer-group peers:
10.1.1.1
Last update: Fri Jan 6 05:40:30 2017
300
22.1.1.2 from 22.1.1.2 (4.4.4.4)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 1
Advertised to non peer-group peers:
10.1.1.1
Last update: Fri Jan 6 05:40:34 2017
300
23.1.1.2 from 23.1.1.2 (4.4.4.4)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 2
Advertised to non peer-group peers:
10.1.1.1
Last update: Fri Jan 6 05:40:37 2017
300
24.1.1.2 from 24.1.1.2 (4.4.4.4)
Origin IGP, metric 0, localpref 100, valid, external
rx path_id: -1 tx path_id: 3
Advertised to non peer-group peers:
10.1.1.1
Last update: Fri Jan 6 05:40:40 2017