H3C S7500 Series Operation Manual page 405

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches
[SwitchC] ospf
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 193.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] network 195.1.1.0 0.0.0.255
[SwitchC] bgp 200
[SwitchC-bgp] undo synchronization
[SwitchC-bgp] group ex external
[SwitchC-bgp] peer 193.1.1.1 group ex as-number 100
[SwitchC-bgp] group in internal
[SwitchC-bgp] peer 195.1.1.1 group in
[SwitchC-bgp] peer 194.1.1.2 group in
4) Configure Switch D.
[SwitchD] interface vlan-interface 4
[SwitchD-Vlan-interface4] ip address 194.1.1.1 255.255.255.0
[SwitchD] interface vlan-interface 5
[SwitchD-Vlan-interface5] ip address 195.1.1.1 255.255.255.0
[SwitchD] ospf
[SwitchD-ospf-1] area 0
[SwitchD-ospf-1-area-0.0.0.0] network 194.1.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] network 195.1.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] network 4.0.0.0 0.255.255.255
[SwitchD] bgp 200
[SwitchD-bgp] undo synchronization
[SwitchD-bgp] group in internal
[SwitchD-bgp] peer 195.1.1.2 group in
[SwitchD-bgp] peer 194.1.1.2 group in
For the configuration to take effect, the reset bgp all command needs to be
executed on all the BGP neighbors.
After the above configuration, because the MED attribute value of the route
1.0.0.0 learned by Switch C is smaller than that of the route 1.0.0.0 learned by
Switch B, Switch D will choose the route 1.0.0.0 coming from Switch C.
If you do not configure MED attribute of Switch A when you configure Switch A
but configure the local preference on Switch C as following:
# Configure the local preference of Switch C
Create ACL 2000 to permit routing information sourced from network 1.0.0.0.
[SwitchC] acl number 2000
[SwitchC-acl-basic-2000] rule permit source 1.0.0.0 0.255.255.255
[SwitchC-acl-basic-2000] rule deny source any
Define a routing policy named localpref, and set the local preference of the
routes matching with ACL 2000 to 200, and that of those unmatched routes to
100.
[SwitchC] route-policy localpref permit node 10
6-31
Chapter 6 BGP Configuration