I need to automatize backup of a /29 subnet routed via 2 PPPoE link.
The scenario:
1) Many PPPoE Server provide PPPoE tunnel to Customers
2) OSPF active beetwen CISCO (front end) and PPPoE Servers
3) Customer router have 2 PPPoE link, primary and backup, whit /29 subnet routed
4) all PPPoE links are always active, but only primary use /29 subnet
5) PPPoE tunnels can be opened on any of PPPoE servers (not server-locked for failover)
6) a RADIUS provide same FRAMED_ROUTE attribute for the two tunnels, but whit an higger
administrative distance for backup link (like 200)
7) when primary link fail, /29 subnet will be routed via backup link (and viceversa)
No problem if the two tunnels are opened on same PPPoE Server, OSPF redistribute to CISCO
only one route for /29 subnet, and PPPoE Server route to primary (lower distance)... al work fine
When the two tunnels are opened on different PPPoE Servers, the OSPF redistibute to CISCO two
entry for /29 subnet, with same distance but two gateway (PPPoE Servers)...
I played whit Routing Filters, matching backup route (like "match all route with distance 200"),
but I cannot change any usefull attribute (like metric) in Actions...
A possible solution can be use "Set Route tag" Actions and configure CISCO (if possible, like ACL/NET MAP?)
to change metric/cost in OSPF input routes... to have onlyone an entry in route table for /29 subnet.
It's a good way?
Other suggestios?
Best regards.