
373
*> 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.
<PE2> 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:
<CE2> 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
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?
*> 100.1.1.1/32 10.2.1.2 0 100 100?
<CE2> display ip routing-table
Routing Tables: Public
Destinations : 9 Routes : 9
Destination/Mask Proto Pre Cost NextHop Interface
10.1.1.0/24 BGP 255 0 10.2.1.2 GE2/1/1
10.1.1.1/32 BGP 255 0 10.2.1.2 GE2/1/1
10.2.1.0/24 Direct 0 0 10.2.1.1 GE2/1/1
10.2.1.1/32 Direct 0 0 127.0.0.1 InLoop0
10.2.1.2/32 Direct 0 0 10.2.1.2 GE2/1/1
100.1.1.1/32 BGP 255 0 10.2.1.2 GE2/1/1
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
200.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0
After you also configure BGP AS substitution on PE 1, the GigabitEthernet interfaces of CE 1
and CE 2 can ping each other: