DNS problems with RH 9
 

I believe that I am having DNS problems with RH 9. I just recently upgraded from RH 7.3 to RH 9. [Prior to the upgrade, I had no problem connecting (via ethernet cable modem with Comcast ISP) to the internet.] I think that it is a DNS problem because I can ping an IP address (198.x.x.x) successfully, but I cannot ping a domain name.

I tried changing the DNS nameservers in my /etc/resolv.conf file, however that does not seem to work.

Could this be an ipv6 related issue?

Does anybody have any suggestions on how to fix this issue?

could it be an iptables issue?

Try stopping iptables, try to resolve some addresses ... if they work, modify your iptables rules to allow DNS traffic udp/53 out.

ryoga92; try http://www.tldp.org/HOWTO/HOWTO-INDEX section;4.4.4DNS
and the rest if it helps. other parts to section4.4-4.4.5,4.4.6,4.4.7,4.4.8and 4.4.10

DNS Problem
 

well ur DNS problem seems to be simple....there can be a number of reasons for not pinging the domain name.....im asuming that u have proper concepts of DNS and have properly configured DNS

1. start the named service

service named start

2. in your network settings add ur domain name in place of DNS

ryoga92; one more try; try thishttp://tldp.org/HOWTO/HOWTO-INDEX/howtos.html page 12 of56, DNS-HOWTO also section 4.4NetWorking
susections:4.4.1-4.4.10

Thanks for your suggestions. :) I'll give them a try and let you know how it turns out!

Thanks ppuru!

Your suggestion worked. Actually, it was the ipchains service that was the culprit. I guess that since I upgraded from RH 7.3 (which uses kernel 2.2.x), ipchains was used instead of iptables. When I stopped ipchains, everything seemed to work. My plan is to prevent ipchains from starting upon boot and start iptables, instead. Am I correct?

Thanks again!
:D

you can remove ipchains totally.

rpm -e ipchains <and the related dependencies>

#chkconfig --list iptables

You can get it started at init level 2

#chkconfig --level 235 iptables on

ppuru,

I haven't removed ipchains yet (although I will soon).
I set iptables for run levels 2,3,4,5. Was there any particular reason for your suggestion of
run levels 235? (Any particular reason for leaving out level 4?)

Also, how can I tell if iptables is properly configured? I used lokkit to specify my firewall with the highest level of security.
Is that good enough?

thanks again!

I have never used lokkit ... just make sure you don'g get into the same situation you had with ipchains.

you can post the output of

#iptables -nvL

here and request for comments/enhancements.

Dear mr. ppuru and mr. ali
ryoga92's problem seems to have been solved. but like Mr. ali said is it ok to make the computer itself as a dns server?