IPTables Issue

Issues related to configuring your network
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amykhar
Posts: 2
Joined: 2008/01/30 19:44:48

IPTables Issue

Post by amykhar » 2008/01/30 19:53:42

I have been having an issue with iptables that I hope somebody can help with. A few months ago, I was goofing off at work and upgrading vbulletin on my personal server. I was uploading the latest version of the code, when I lost the connection to the server about halfway through the upload. Initially, I assumed the server needed to be rebooted, and put in a support call. They responded that the server was up and fine.

But, I still couldn't connect at work. Tracert seemed at the time to indicate that the connection wasn't getting past my company's router. When I still couldn't connect from work the next day, I assumed that somebody at work decided I shouldn't be goofing off anymore and had blocked the server. So, I left it at that and used Tor to get to my server when I absolutely needed to.

Over time, I gained access to the company's router, and learned that my server was not blocked. And, running tracert again showed that the traffic was stopping at my server's end - not the company's.

So, I used remote access to get to another computer where I could ssh into my server. I turned off iptables, and boom. I could access my server from work.

Now, I never added a rule to block my work IP address. So, I'm assuming something in Centos did it automatically. Perhaps in response to the speed and large number of files I was uploading that day.

If I do an iptables -List, absolutely no rules show up.

So, if I want to get in from work, I have to ssh in from another location, and turn off the firewall.

How can I figure out what blocked my work IP address and even more importantly STOP the server from blocking me?

Amy

michaelnel
Posts: 1478
Joined: 2006/05/29 16:50:11
Location: San Francisco, CA

IPTables Issue

Post by michaelnel » 2008/01/30 19:56:38

Check to see your IP is not listed in /etc/hosts.deny

amykhar
Posts: 2
Joined: 2008/01/30 19:44:48

Re: IPTables Issue

Post by amykhar » 2008/01/30 22:45:10

hosts.deny does not have any blocked hosts in it.

yyagol
Posts: 1015
Joined: 2006/06/10 18:27:44
Location: 32 4′N 34 47′E
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Re: IPTables Issue

Post by yyagol » 2008/02/01 08:28:02

put logs on traffic and view the problem
if there are no rules define nothing should be blocked or reject
add to syslog.conf the line kern.warn /var/log/kernel.warning.log
and restart syslog daemon ,this can help you monitor the problem ,every rejecr/drop
will be logd to as warning .

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