cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

Welcome to the Cisco Small Business Community

Have a question? Click on a topic board below to get started in the community.

218
Views
0
Helpful
0
Replies
bhushh009
Beginner

Routing Loop because of Default route generated by ABR

Consider
two PEs connected to one VPN customer site. PE-CE links are in non-zero OSPF area, and area is configured as stub. As a result, both PEs originate default summary LSA (per RFC 2328). But at the same time both PEs run in RFC 3509 mode (because area 0 is not configured). As a result, per RFC 3509 they compute default route via each other based on default summary LSA received from each other. Now if for some packet default route entry is used for forwarding, packet is looped between two PEs.

In Nutshell, both these implementation are contradicting to each other.

I have made set up in my lab and seeing same behavior.
      vprn                         stub
PE1--------------PE2------------------------------|
|                                                 CE
|-----------------PE3-----------------------------|
                                stub

Between PE1 , PE2 and PE3 = > VPRN
Between PE2, PE3 and CE=> OSPF inside VPRN- STUB NON ZERO area. Both links PE2 -CE and PE3-CE is in same stub area.

 Because of default route generated by PE2 and PE3, there is routing loop between PE and CE. AM i missing any configuration? IS there any ways to suppress default route on PE?
Anybody come across this situtaion before?
0 REPLIES 0