Steve Kleene wrote:
I started the tcpdump command, then started "ping debian.org", and got the following:
Looks like the replies get lost somehow. At least afaict they do not make it into the interface of your computer (even dropping packets through iptables should still make them appear in tcpdump afaik). One idea (still strange that pinging the router works though): check that no other computer in your network is using ip 192.168.0.4 (arping 192.168.0.4 should reply nothing, ping 192.168.0.4 should not report doubles (albeit the latter isn't as reliable since some computers don't reply to icmp pings); you could also watch tcpdump for a while and look out for arp replies for that ip, it should always be your MAC address). Also check the error count in "ifconfig eth0", maybe cabling is half broken. If that brings nothing, I'd suspect the problem is at the router.
Christian.