networking stopped working on sarge

[Kevin Murphy]

I'm probably missing something obvious here, but my sarge box suddenly became unable to access the internet (and vice versa) the other day.  There were two unusal events that day, and unfortunately, many ill-advised experiments in mixing coffee and beer later,  I don't remember the order of the events and the onset of my problems ;-)   1) I updated via synaptic -- however, nothing should have been updated, if I understand how synaptic works, because one package failed to install correctly (due to dependency problems introduced by a non-testing package).   2) Also on the same day, power was cut from the box (kicked power cable).  The fsck made about a dozen repairs upon startup.   Most of the time, I can't ping anything from the box, even by IP address, and I can't ping the box from the outside.  When I ping from the box, it says "Destination Host Unreachable".   Bizarrely, there was a stretch for a few minutes at one point when networking was working.   Anyway, I'm not sure what to look for.  Here's what I've done so far:   * I checked the cable, and that is OK.  As a check, I unplugged a working cable from the back of another computer and plugged it into my sarge box, to no avail.   * I rebooted the computer.   * I did /sbin/ifconfig -a, which shows the machine's correct IP address under eth0 (I'm typing the following, so excuse any typos):   eth0    Link encap:Ethernet   HWaddr blah     inet addr:192.168.0.2 Bcast:192.168.0.255  Mask:255.255.255.0     inet6 addr: blah     UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1     RX packets: 3507 errors:1 dropped:0 overruns:0 frame:0     TX packets: 2789 errors:0 dropped:0 overruns:0 carrier:0     collisions:0 txqueuelen:1000     RX bytes:801243 (782 KiB)  TX bytes:262918 (256.7 KiB)     Interrupt: 11 blah   * I did /sbin/route, and it spits out:   192.168.0.0   *    255.255.255.0 U 0 0 0 eth0   immediately, but 30 or so seconds later (!?), it spits out:   default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0   Is that delay unusual behavior?   * I looked at /var/log/syslog, and while I don't understand very much that I see there, the only strange thing (to me) were a few messages about certain UDP packets that appear somewhat sporadically every once in a while, usually in bursts of one message every couple minutes.  These message occur even while I can't get anything else to work, btw.   * Top shows low CPU usage, 46M memory free.   * df -k shows plenty of space.   * I updated (via manual download on another machine, copy to CDROM, and dpkg) from kernel-image-2.6.3-1 to kernel-image-2.6.7-1-k,  just for the hell of it.   * I have an AMD K7 system with a Kingston KNE100TX NIC.  I'm using a DLink DI-514 router, and other machines on that router are working fine.   Sorry for the long message.  What should I do next?   Thanks, Kevin Murphy