network working one way only?

[richard lyons <richard@the-place.net>]

I must be in an exceptionally dim mood today.  I just noticed that my 
laptop, on which I am writing this, is not accessible from other boxes 
on the network.  Ping, nfs, cups are all failing to connect.  Must be 
something I have upgraded, I suppose.  hosts.allow has all the usual 
entries, I can ping out to the network, and send mail normally through 
my firewall machine to the adsl router.  Name serving seems to be 
working, though I cannot check with dig as it is not installed on this 
machine and I never did find what package provides it.

I cant at the moment think what to look for next -- quick hint anyone?

-- 
richard