> This is a *single area* ospf environment, that has been stable for years. > But now suddenly is having issues with new ospf neightbor adjacencies , which > are riding a 3rd party transport network
I have seen this in the lab before, was related to the size of the LSA. > Anyone ever experienced anything strange with underlying transport network > mtu possibly causing ospf neighbor adjacency to be broken ? I'm asking if > the underlying 3rd party transport layer 2 network >has a smaller mtu than the endpoint ospf ip interface have, could this cause >those ospf neighbors to not fully establish ? You can check this with a ping of your mtu size set with the df bit set > .and I'm also asking this if the single ospf area has grown large enough to > cause some > sort of initial database packet to be larger than that underlying 3rd party > mtu is providing If you have a large amount of routers in your area the LSA size will grow, we saw a problem in testing when we injected 2000 prefixes into the area and the OSPF neighbour would not come up. On a cisco router you can set 'buffers huge' as a work around. Richard
