L3Vpn Ibgp Pe-Ce; L3Vpn Ibgp Pe-Ce Overview - Cisco ASR 9000 Series Routing Configuration Manual

Implementing BGP

L3VPN iBGP PE-CE

The following is sample output from the show bgp community graceful-shutdown command displaying
the graceful maintenance feature information:
RP/0/0/CPU0:R4#show bgp community graceful-shutdown
BGP router identifier 192.168.0.4, local AS number 4
BGP generic scan interval 60 secs
BGP table state: Active
Table ID: 0xe0000000 RD version: 18
BGP main routing table version 18
BGP scan interval 60 secs
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* 5.5.5.5/32 10.10.10.1 88 0 1 ?
Processed 1 prefixes, 1 paths
The following is the sample output from the show bgp neighbors command with the ip-address and
configuration argument and keyword to display graceful maintenance feature attributes:
RP/0/0/CPU0:R1#show bgp neighbor 12.12.12.5
...
Graceful Maintenance locally active, Local Pref=45, AS prepends=3
...
For Address Family: IPv4 Unicast
...
GSHUT Community attribute sent to this neighbor
...
**************************************************************************
RP/0/0/CPU0:R1#show bgp neighbor 12.12.12.5 configuration
neighbor 12.12.12.5
remote-as 1 []
graceful-maintenance 1 []
gr-maint local-preference 45 []
gr-maint as-prepends 3 []
gr-maint activate []
The following is the sample output of the show rpl community-set command with graceful maintenance
feature attributes displayed:
RP/0/0/CPU0:R5#show rpl community-set
Listing for all Community Set objects
community-set gshut
graceful-shutdown
end-set
The following is the sample of the syslog that is issued when a BGP neighbor that has graceful maintenance
activated, comes up. It is a warning text that reminds you to deactivate graceful maintenance after convergence.
RP/0/0/CPU0:Jan 28 22:01:36.356 : bgp[1056]: %ROUTING-BGP-5-ADJCHANGE : neighbor 10.10.10.4
Up (VRF: default) (AS: 4)
WARNING: Graceful Maintenance is Active
L3VPN iBGP PE-CE
The L3VPN iBGP PE-CE feature helps establish an iBGP (internal Border Gateway Protocol) session between
the provider edge (PE) and customer edge (CE) devices to exchange BGP routing information. A BGP session
between two BGP peers is said to be an iBGP session if the BGP peers are in the same autonomous systems.

L3VPN iBGP PE-CE Overview

When BGP is used as the provider edge (PE) or the customer edge (CE) routing protocol, the peering sessions
are configured as external peering between the VPN provider autonomous system (AS) and the customer
network autonomous system. The L3VPN iBGP PE-CE feature enables the PE and CE devices to exchange
Border Gateway Protocol (BGP) routing information by peering as internal Border Gateway Protocol (iBGP)
instead of the widely-used external BGP peering between the PE and the CE. This mechanism applies at each
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
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