Running OSPF between two 4507s Gig ports and the neighbors are not coming due to the DB packets being larger than the MTU on both ends. (Not an MTU mismatch as both sides are the same and the "mtu-ignore" did not help.)
Problem is that the two 4500 interfaces are connected via L2TP which lowers the MTU and the OSPF DB tried using 1492 bytes which is too large.
Any way to change OSPF to not use the full 1500 bytes? I would not want to lower the MTU on LAN/Gig interfaces and tweak MSS etc....
Try changing the ip mtu value on the interface.