H3C Technologies H3C SR8800 - Manual (Page 358)

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Enable BGP update packet debugging on PE 2. You can see that PE 2 advertises the route to
100.1.1.1/32, and the AS_PATH is 100 600.
terminal monitor
terminal debugging
debugging bgp update vpn-instance vpn1 verbose
refresh bgp vpn-instance vpn1 all export
*0.4402392 PE2 RM/7/RMDEBUG:
BGP.vpn1: Send UPDATE to 10.2.1.1 for following destinations :
Origin : Incomplete
AS Path : 100 600
Next Hop : 10.2.1.2
100.1.1.1/32,
Issue the display bgp routing-table peer received-routes command on CE 2. You can see that CE 2 did
not receive the route to 100.1.1.1/32.
display bgp routing-table peer 10.2.1.2 received-routes
Total Number of Routes: 4
BGP Local router ID is 10.2.1.1
Status codes: * - valid, ^ - VPNv4 best, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.1.1.0/24 10.2.1.2 0 100?
*> 10.1.1.1/32 10.2.1.2 0 100?
* 10.2.1.0/24 10.2.1.2 0 0 100?
* 10.2.1.1/32 10.2.1.2 0 0 100?
2. Configure BGP AS number substitution
# Configure BGP AS number substitution on PE 2.
system-view
[PE2] bgp 100
[PE2-bgp] ipv4-family vpn-instance vpn1
[PE2-bgp-vpn1] peer 10.2.1.1 substitute-as
[PE2-bgp-vpn1] quit
[PE2-bgp] quit
The output shows that among the routes advertised by PE 2 to CE 2, the AS_PATH of 100.1.1.1/32 has
changed from 100 600 to 100 100:
*0.13498737 PE2 RM/7/RMDEBUG:
BGP.vpn1: Send UPDATE to 10.2.1.1 for following destinations :
Origin : Incomplete
AS Path : 100 100
Next Hop : 10.2.1.2
100.1.1.1/32
Display again the routing information that CE 2 receives and the routing table:
display bgp routing-table peer 10.2.1.2 received-routes
Total Number of Routes: 5
BGP Local router ID is 10.2.1.1
Status codes: * - valid, ^ - VPN best, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale