H3C Technologies H3C SR8800 - Manual (Page 273)

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4. Configure different attribute values for the route 1.0.0.0/8 to make Router D give priority to the
route learned from Router C:
{
Method I
Specify a higher MED value for the route 1.0.0.0/8 advertised to 192.1.1.2 to make Router
D give priority to the route learned from Router C.
# Define ACL 2000 to permit the route 1.0.0.0/8
[RouterA] acl number 2000
[RouterA-acl-basic-2000] rule permit source 1.0.0.0 0.255.255.255
[RouterA-acl-basic-2000] quit
# Define routing policy apply_med_50 that sets the MED value of route 1.0.0.0/8 to 50, and
routing policy apply_med_100 that sets the MED value of route 1.0.0.0/8 to 100.
[RouterA] route-policy apply_med_50 permit node 10
[RouterA-route-policy] if-match acl 2000
[RouterA-route-policy] apply cost 50
[RouterA-route-policy] quit
[RouterA] route-policy apply_med_100 permit node 10
[RouterA-route-policy] if-match acl 2000
[RouterA-route-policy] apply cost 100
[RouterA-route-policy] quit
# Apply routing policy apply_med_50 to the route advertised to 193.1.1.2 (Router C), and
apply routing policy apply_med_100 to the route advertised to 192.1.1.2 (Router B).
[RouterA] bgp 100
[RouterA-bgp] peer 193.1.1.2 route-policy apply_med_50 export
[RouterA-bgp] peer 192.1.1.2 route-policy apply_med_100 export
[RouterA-bgp] quit
# Display the BGP routing table on Router D.
[RouterD] display bgp routing-table
Total Number of Routes: 2
BGP Local router ID is 194.1.1.1
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
*>i 1.0.0.0 193.1.1.1 50 100 0 100i
* i 192.1.1.1 100 100 0 100i
The route 1.0.0.0/8 learned from Router C is the optimal.
{
Method II
Specify different local preferences for route 1.0.0.0/8 on Router B and C to make Router D
give priority to the route learned from Router C.
# Define ACL 2000 to permit the route 1.0.0.0/8 on Router C.
[RouterC] acl number 2000
[RouterC-acl-basic-2000] rule permit source 1.0.0.0 0.255.255.255
[RouterC-acl-basic-2000] quit