Welcome to the most active Linux Forum on the web.
Go Back > Forums > Linux Forums > Linux - Security
User Name
Linux - Security This forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.


  Search this Thread
Old 04-28-2004, 10:01 AM   #1
Registered: Feb 2003
Location: Buffalo, NY
Distribution: Novell Linux Desktop
Posts: 159

Rep: Reputation: 30
ping not resolving names - iptables

I am using iptables and i was able to setup the chains to accept pings (icmp), i set the same rule for the output as the input "-A INPUT -p icmp -j ACCEPT" "-A OUTPUT -p icmp -j ACCEPT" but am still not able to resolve names on the box. I can ping everything by ip address but not name. when i shut down the iptables service i can ping everything by name so this leads me to believe that it's a iptables config issuse. what needs to be opened for pings to resovle?

Old 04-28-2004, 08:09 PM   #2
Senior Member
Registered: Mar 2003
Distribution: Fedora
Posts: 3,658

Rep: Reputation: 69
Sounds like the problem is with DNS hostname lookups rather than with the ping traffic itself. Try allowing DNS traffic in and out to your ISPs DNS servers.
Old 07-29-2004, 12:32 AM   #3
Registered: Dec 2003
Location: Netherlands
Distribution: SuSe 9.0
Posts: 44

Rep: Reputation: 15
Make sure u have the folowing rulez:

#Enable Nameresolving
$IPTABLES -A OUTPUT -o eth0 -p udp --destination-port 53 -j ACCEPT
$IPTABLES -A INPUT -i eth0 -p udp --source-port 53 -m state --state ESTABLISHED -j ACCEPT

#Enable icmp this also fix that people or hackers cannot ping u from the outside world./inside.
$IPTABLES -A INPUT -p icmp --icmp-type echo-request -i eth0 -j ACCEPT
$IPTABLES -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
$IPTABLES -A INPUT -p icmp --icmp-type echo-reply -j ACCEPT

This wil fix the prob.
After u have checked your resolv.conf file

have fun



Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
resolving names through a router Y0jiMb0 Linux - Networking 4 11-15-2005 05:05 PM
temporary issues resolving names mrog Debian 1 02-18-2005 03:21 PM
NetBIOS names not resolving Xhalman Linux - Networking 0 02-16-2004 03:38 PM
Mandrake 9.1 not resolving domain names erikbennett Mandriva 2 10-06-2003 05:50 PM
Apache is resolving names to ip? danimaldaisy Linux - Networking 3 12-18-2002 01:54 AM > Forums > Linux Forums > Linux - Security

All times are GMT -5. The time now is 07:19 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration