[Courses] [Security] ICMP being blocked?

[Terri Oda]

I've got a question too, actually.

When I switched to debian-testing, my network card seems to have gotten 
reconfigured or something so that I can't seem to ping anyone outside of my 
local network anymore.  I could ping my gateway, even when I used the 
non-local address to get to it, but nothing else I tried (google.com, 
ncf.ca, linuxchix.org, and a handful of IPs...) would reply.  DNS was 
working fine so it wasn't a lookup issue (that's what I thought at first) 
and I could browse the web and ssh in to various machines, but no ping for me!

I thought it was just some weird default iptables setting in debian, but 
when I bothered to go look, as far as I could tell, iptables isn't running. 
(nor ipchains, although my kernel being 2.4.17 or so, it wouldn't be able 
to run anyhow, right?)  Is there any other thing that might be causing ICMP 
to be blocked?

I know my gateway hasn't changed its settings, but my pcmcia config files 
have changed. I had pcmcia-cs installed even though I'm using the in-kernel 
drivers and so I got a new batch of config files and reconfigured those 
rather than overwriting them with the old ones... I'll probably go back to 
the old ones and see if that solves the problem, but since I don't have it 
on the network right now it seems silly to try and guess what might be 
wrong without being able to test.

I suppose it's possible that everywhere I tried to ping was just rejecting 
me, but it seems unlikely.

  Terri