iptables breaks internet

ShadyMilkman · n00b Joined: 20 Apr 2002 Posts: 57

Well, I have my system running great and iptables compiled into my kernel, and I can add rules and stuff fine, but the problem is that as soon as I add a rule, to say, INPUT, my internet effectively shuts down. It acts as if my cable modem just got unplugged from the wall. If I remove the rule from iptables the internet then works again. Maybe it has to do with the way I'm writing the rule? Anyway, here's an example of something I'll do:

Aruspex · n00b Joined: 28 Jun 2002 Posts: 51 Location: Brick, NJ

Is your default polcy set to Deny? Type 'iptables -L' to check.

If this is the case, you would either need to set it to accept or create rules that allow traffic through.

[edit] I am sorry. That was one of the more stupid things I have done :oops:

I should have read your whole post...

Try going to google and searching for a sample firewall script. This will atleast let you know if you are building the rules properly.
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rizzo · Posted: Mon Jul 15, 2002 6:42 pm Post subject:

Perhaps post your entire iptables script would be more helpful for the forum crowd.

ShadyMilkman · n00b Joined: 20 Apr 2002 Posts: 57

That command was not a script..... I simply typed it in as root. I'll try a script when I get home.

Nitro · Last edited by Nitro on Mon Jul 15, 2002 8:09 pm; edited 1 time in total

It isn't the command. I think you have a problem with your kernel and netfilter. Could you supply us with the output of:

ShadyMilkman · n00b Joined: 20 Apr 2002 Posts: 57

Nitro · Posted: Tue Jul 16, 2002 12:18 am Post subject:

You have one wierd problem.

You tried recompiling your kernel? Maybe something is broke.

If you want to play with your kernel, my server has the following, and it does work:

dcloues · Posted: Tue Jul 16, 2002 5:19 am Post subject:

Try replacing the line with