Hello All,

I have a gateway server which is currently listening for TCP/UDP packets and authenticating clients if their details IP/MAC is known.

I have a couple of clients who's network equipment sends ICMP pings to a remote site to determine internet connectivity and I'm missing those resulting in the client's device not logging in.

Is there some way that I can write a listener similar to a listener for TCP/UDP sockets which will listen to ICMP packets and pick up the IP and MAC address of the sender upon which I can perform processing on?

Thanks
Anubis.

well, icmp packets can be received and analyzed. you can use, e.g., tcpdump 'icmp[icmptype] = icmp-echo' to take a look to see what you can find.