demand:
FR between R1 and R5 are the main link, under normal circumstances area 35, area 56, and R1 is S3 / 0 / interface network traffic to go through FR 0 where the link, but this chain Road unstable, in the case of frame relay link interruption, traffic needs to be switched to the backup link Ethernet R1 and R5 are, if the primary link recovers, traffic is automatically switched back;
Topology:
Description: When R1 R5 default access walking FR, frame relay line fault, go g0 / 0/1 of the access area 15 R5;
When the frame relay circuit returns to normal, then switch back;
Logical topology is as follows:
Configuration:
I can be established by area 15 virtual links to solve this problem by modifying the link cost value, realize link backup;
R1 configuration:
ospf 1 area 15 vlink-peer 10.1.5.5 interface g0/0/1 ospf cost 20000
R5 configurations:
ospf 1 area 15 vlink-peer 10.1.1.1 interface g0/0/1 ospf cost 20000
Demand Verification:
正常情况下去tracert 10.1.56.6，下一跳走10.1.145.5
手动将R1的s1/0/0端口down掉
interface s1/0/0 shutdown
等R1的S1/0/0口回复正常，则线路有切换回来，即可；
知识点：