Is there a Block/Allow file I'm missing?

jbruyet · 10-27-2011, 02:45 PM

Hey all, I've installed a couple of Linux servers here at my work. They're basically just file repositories at this time but hey, they run Linux and they're problem free. Until now. We were almost out of IP addresses so I moved us from one big subnet to three subnets: 1.xxx, 2.xxx and 3.xxx. All of my workstations are in the 1.xxx or the 3.xxx subnets, all of my servers are in the 2.xxx subnet and we're all separated by a Fortigate router. If I set my workstation address to 2.xxx I can get into everything, but if I set my workstation address to 1.xxx I can get into everything except my Debian 6 server. I can ping the server, I can run NMAP on it and see all of the ports but I can't ssh into it or access it from a web browser. If I change back to a 2.xxx address I can do all of these things. Does my Debian server have some kind of ACL list running on it? I didn't set up anything like that that I know of but I'm still kind of new to Linux.

Thanks,

Joe B

chrism01 · 10-28-2011, 01:16 AM

Possibly iptables (aka firewall); try

Code:

iptables -nvL

on target system as root

jbruyet · 10-30-2011, 04:05 PM

Hi chrism01, here's the output of your iptables code:

root@BigDeb:/home/jobee# iptables -nvL
Chain INPUT (policy ACCEPT 276 packets, 42817 bytes)
pkts bytes target prot opt in out source destination

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination

Chain OUTPUT (policy ACCEPT 117 packets, 28661 bytes)
pkts bytes target prot opt in out source destination
root@BigDeb:/home/jobee#

I don't have any idea what any of this means but I'm guessing that since nothing is listed under what I believe to be column headings my problem isn't being caused by iptables. Do you see anything here?

Thanks,

Joe B

jbruyet · 11-01-2011, 01:18 PM

So there aren't any Access Control Lists that could be automatically configured for current subnet access? I can't find anything that's blocking access. It's for sure not a routing issue because I can access a CentOS server that's plugged into the same switch. Any one have any guesses for something to look into???

Thanks,

Joe B

chrism01 · 11-02-2011, 01:15 AM

Have you checked /etc/hosts.allow, /etc/hosts.deny ? (Assuming correct locations for Debian)
Also check the /etc/ssh/sshd_config on server end.

jbruyet · 11-02-2011, 05:11 PM

Chrism01, I added the following line to hosts.allow (it was blank, and it WAS under /etc) but it didn't help:

ALL : 192.168.1.0/255.255.255.0 \

I checked the hosts.deny file and it was blank. I uncommented the ListenAddress 0.0.0.0 line but that didn't help either. Any other ideas? Anyone else?

Thanks,

Joe B