Im troubleshooting a strange phenomen in our Routed campus LAN, wich consist basically of 6500 with CatOS and MSFC2 with IOS 12.1 / 12.2 and OSPF as routing protocoll.
Here is the cenario:
From a given source to a given destinageion there are 4 hops. Each steps from the source to the destination has been verified, and there are only one route to each. The routes hasn't changed the last 24 hours on any of the involved routers.
When i ping from the source to the destination, and connects a sniffer to the same port as the desionation host is connected, i see TTL=1 in the echo packet.
The real problem is actually that the connectivity is intermitted. Sometimes the last router sends a icmp-dest unreachable and sometimes i can see tha icmp-echo reply from the destination host (with a TTL=64).
Does anyone have an idea or have had simular experiences?
I would be grateful for all answers and tips.