Tunnel interface limit?

[dennylester]

We recently converted 22 sites (1 host 21 remotes) from Frame to MPLS. I now want to use a routing protocol. My routers do not support BGP so I'm thinking OSPF.

Unfortunately my MPLS carrier won't support OSPF so I'm thinking a bunch of tunnels from each remote to my host site and run OSPF over those tunnels.

Most host site has two T1's running into this MPLS network. We should have done MLPPP but didn't think about it until after the fact. So, 21 remote sites each needing two tunnels, one for each T1 Interface at the host, would be 42 tunnel interfaces.

We plan on moving locations in the next year and at the new site I can have the two new T1's bundled together using MLPPP. For now we cannot afford any downtime to bundle these two together so we'll just live with round robin routing.

Does this sound reasonable? Does anyone see any problems with this thinking?

Denny

[Richard Burts]

Denny

Without knowing a bit more about your environment it is difficult to give really good answers but this may help. The only hard limit on the number of tunnels is the limit imposed by IDBs (which may vary by platform and by IOS version) but you are certainly not near the limit. From a practical standpoint there might be a performance concern about the number of tunnels and of the number of OSPF neighbors but I doubt that the number of tunnels you are talking about will be an issue there. As a point of reference I have a customer running GRE tunnels (in conjunction with IPSec) to over 200 remote locations (using EIGRP as the routing protocol) and it is doing fine (on 7206 router at the head end). If you need more information please clarify what your environment is.

HTH

Rick