Hi, I have this funny networking problem which I can't seem to understand. Please be patient, this is going to be a bit long to explain :)
I'm setting up this debian (woody r1, but upgraded to sid, stable enough for me!) box to run as a second layer of firewall/gateway for our small office network (one first layer + dmz + then a second layer). This box is to replace a current firewall which is running on WindowsXP. (disclaimer: I'm pretty familiar with RH, but have just been trying to switch to debian in the last one month after RH decided to drop. Have been running debian on a few machines now, including my own Thinkpad). During the setup, everything is working, both NICs are doing ok. Then I shut it down to move it to the location it's supposed to be at. After booting up, I got a few weird networking issues: 1- The network interfaces (eth0, eth1) seems to switch places, depending on the number of cables I plug in the cards (one card plugged, or both cards plugged). E.g., if I plug in only one cable, eth0 is on one card. If I plug in both cables, eth0 moves to the other card. Shouldn't the network interfaces stay static (I don't remember RH ever do this, as our outer firewall is running RH9)? 2- Regardless of problem #1, I plugged in both cables. Now, I can ping machines on the network which eth1 (internal) is connected to, and I can ping machines on the network which eth0 (external) is connected. Looks good. The problem is, I can only do ping. No other protocols work, e.g. http, ftp, etc. BUT I can ssh into the box on eth1. Looks like a route problem. Checked my route, seems ok to me: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.20.0 * 255.255.255.0 U 0 0 0 eth1 192.168.10.0 * 255.255.255.0 U 0 0 0 eth0 default 192.168.10.1 0.0.0.0 UG 0 0 0 eth0 Weird problem. So I decided to put back our XP box to troubleshoot this debian thingy. I just connect one cable to eth1 (which obviously switches card again). And I can still ping from that box to any machine, including those on the internet. I still can ssh into the box, but no other protocol can get out. As I said, the networking was working fine, as I upgraded a bunch of things thru apt-get after I installed debian, and tested quite bit, including scanning with nessus, before I decided it's ok to put it to work. In order to just troubleshoot one card at a time, I let down eth0 (ifconfig eth0 down) for now, and worked on eth1, and put the machine in internal network. Same problem, I ping any machine anywhere, I can ssh into the machine, but no other protocol can get out. (DNS is working though). Oh, and this should have nothing to do with the firewall rules, as I drop all rules during testing. Traceroute works sporadically on the local network, works on some machines, not on others. But I can ping. After shutting down eth0, and put in the default gw for eth1, here's what "route -n" gives: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.20.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 0.0.0.0 192.168.20.1 0.0.0.0 UG 0 0 0 eth1 Here's some info: uname -na : Linux base 2.4.22 #1 Wed Nov 19 13:13:23 EST 2003 i686 GNU/Linux iptables: 1.2.9-1 Network card: Dlink DFE-530TX (via-rhine module) dmesg file is attached here. Thanks for any help with this. kk __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/
dmesg
Description: dmesg
