This document explains behaviour of Cisco routers running IOS when configuring soft-reconfiguration Inbound
Possible scenarios:
1. - When the BGP neighbour is not route refresh capable:
1.1 No soft-reconfiguration inbound configured
1.2 Soft-reconfiguration inbound configured
2. - When the BGP neighbour is route refresh capable:
2.1 No soft-reconfiguration inbound configured
2.2 Soft-reconfiguration inbound configured
Descriptions and outputs
1. - No route refresh capability:
1.1 No soft-reconfiguration inbound configured
- Route Refresh messages are not sent
R2#clear bgp all 65000 soft in
R2#
R2#
- IOS-XR router won’t keep a copy of the bgp routing table
R2#sh bgp all neighbors 172.16.26.6 received-routes
For address family: IPv4 Unicast
% Inbound soft reconfiguration not enabled on 172.16.26.6
1.2 Soft-reconfiguration inbound configured
- Route refresh messages are not sent
R2#clear bgp all 65000 soft in
R2#
R2#
- IOS-XR router will keep a copy of the bgp routing table
R2#sh bgp all neighbors 172.16.26.6 received-routes
For address family: IPv4 Unicast
BGP table version is 31, local router ID is 172.16.102.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 6.6.6.0/24 172.16.26.6 0 0 65000 ?
* 172.16.26.0/24 172.16.26.6 0 0 65000 ?
*> 172.16.30.0/24 172.16.26.6 0 0 65000 ?
*> 172.16.106.0/24 172.16.26.6 0 0 65000 ?
Total number of prefixes 4
2.- With Route refresh capability:
2.1 No soft-reconfiguration inbound configured
- Route refresh messages will be sent when needed
R2#clear bgp all 65000 soft in
*Apr 1 13:51:18.035: BGP: 172.16.26.6 sending REFRESH_REQ(5) for afi/safi: 1/1
*Apr 1 13:51:18.035: BGP: 172.16.26.6 send message type 5, length (incl. header) 23
- IOS-XR router won't keep a copy of the bgp routing table
R2#sh bgp all neighbors 172.16.26.6 received-routes
For address family: IPv4 Unicast
% Inbound soft reconfiguration not enabled on 172.16.26.6
2.2 Soft-reconfiguration inbound configured
- Route refresh messages are not sent
R2#clear bgp all 65000 soft in
R2#
R2#
- IOS-XR router will keep a copy of the bgp routing table
R2#sh bgp all neighbors 172.16.26.6 received-routes
For address family: IPv4 Unicast
BGP table version is 37, local router ID is 172.16.102.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 6.6.6.0/24 172.16.26.6 0 0 65000 ?
* 172.16.26.0/24 172.16.26.6 0 0 65000 ?
*> 172.16.30.0/24 172.16.26.6 0 0 65000 ?
*> 172.16.106.0/24 172.16.26.6 0 0 65000 ?
Total number of prefixes 4
Regards
Nelson
Nelson Gull
| Cisco Systems Limited |
