[j-nsp] Capturing/displaying contents of incoming packets

[Tom Storey]

Hi all,

I am trying to debug some stubborn circuits that just dont seem to
want to work. I can see incoming packets being recorded on both
interfaces (10GE, both on the same router), but I cannot ping across
either link. Ive verified with the owner of the router at the other
end and we are using the correct subnets, and the same interface
configuration, but neither of us can ping the other.

I am interested to try and work out what is in the packets that are
coming in to work out if they belong to the routers they are supposed
to at the opposite end of each link, or where they are from.

Im wondering if there is some way to output the details like a TCP
dump, or capture to a pcap file which can be read by Wireshark et al?
The later seems possible on certain models, but not the gear in
question here, an MX960 with DPCEs.

The rate of packets is extremely low, as in 1 or 2 packets a minute,
but would potentially reveal a lot to me at this stage. Unfortunately
theres a bit of an air (and sea) gap between me and the router in
question, so any form of local troubleshooting is out of the question
at the moment.

Thanks,
Tom