Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

sham-link endpoint advertisement

can you pls help me to understand why below sentence is true ? why we can not advertise endpoints via OSPF ?

iBGP, not OSPF, must always advertise the sham link endpoints

1 REPLY
Cisco Employee

sham-link endpoint advertisement

Hello,

can you pls help me to understand why below sentence is true ?

Because otherwise, it would be a chicken-and-egg problem. The sham-link is configured using the opposite PE's IP address in a particular VRF - it is basically a targeted OSPF session between two distant PEs. Assuming that you want OSPF to carry this IP address, you have an unsolvable situation: without knowledge where this IP address is located, the sham-link can not go up, and if the sham-link can not go up, you can not find out where this IP address is located.

Best regards,

Peter

187
Views
0
Helpful
1
Replies