On Mon, 20 May 1996 11:25:20 GMT, vuori@sci.fi (Valtteri Vuorikoski) wrote:

>On Sun, 19 May 1996, John F. Woods wrote:

>> According to my modem lights and netstat -picmp, someone out there in IP land
>> seems to be constantly pinging my system (not a flood ping, thank goodness).
>> Is there an existing program that can be used to figure out the source of these
>> packets?  I assume I can knock something together using BPF, but I am hoping
>> that someone here has already solved this problem...

> tcpdump -i your-happy-network-interface icmp

Also, remomeber that not all packets that come across the line are IP packets - If you are running
PPP on the link, it may have negotiated with the other side to do LQM (Link Quality Monitoring), which
is done by exchanging informational packets every few seconds so both sides know how well the other
is doing. Since these packets are LCP packets, IP never sees them. I don't recall if tcpdump will show
link layer packets or not.