network unreachable

[Alexandru Cabuz <alexcabuz@wanadoo.fr>]

Hi,

I got two computers in my office, both using Debian Sarge. One 2.6.9, the 
other 2.6.7.

They both can ping the outside world (like google.com), but they can't ping 
each other. 
Let's call them machine A and machine B.

When I try to ping B from A I get 
connect: Network is unreachable

When I try to ping A from B I get
From [IP of machine B] icmp_seq=1 Destination Host Unreachable
From [IP of machine B] icmp_seq=2 Destination Host Unreachable
From [IP of machine B] icmp_seq=3 Destination Host Unreachable

and so on and so forth...

I can browse the internet from both of them, read my mail, etc. But I can't 
for example ssh to either of them.

I have even turned off the firewalls on both of them, and I still get this 
error. Something is weird, because I have installed sarge on both these 
machines numerous times and never have I gotten this kind of error...

Any suggestions?

Alex.