I assume you've turned off IPX and IPV6 and then rebooted your system.
If not do so to effect the changes.
Next test name resolution...
e.g.
nslookup
> set all
You'll get something like this back...
Default server: 192.168.0.2
Address: 192.168.0.2#53
Default server: 64.81.111.2
Address: 64.81.111.2#53
Set options:
novc nodebug nod2
search recurse
timeout = 0 retry = 3 port = 53
querytype = A class = IN
srchlist = netrslts.com
>
Note the default server. This is the DNS to which your machine is trying first before falling through to your ISP's.
Now perform a search
>
www.linuxquestions.org
Server: 192.168.0.2
Address: 192.168.0.2#53
Non-authoritative answer:
Name:
www.linuxquestions.org
Address: 64.179.4.149
>
How is the response?
Now set the DNS queries to your ISP's servers one at a time and try them.
> server 64.81.111.2
Default server: 64.81.111.2
Address: 64.81.111.2#53
>
Again perform a search. Is the response immediate?
>
www.linuxquestions.org
Server: 64.81.111.2
Address: 64.81.111.2#53
Non-authoritative answer:
Name:
www.linuxquestions.org
Address: 64.179.4.149
>
Turn on debugging to see more info...
> set debug
>
www.linuxquestions.org
Server: 64.81.111.2
Address: 64.81.111.2#53
Non-authoritative answer:
Name:
www.linuxquestions.org
Address: 64.179.4.149
>set recurse on
>
>
www.linuxquestions.org
Server: 64.81.111.2
Address: 64.81.111.2#53
------------
QUESTIONS:
www.linuxquestions.org, type = A, class = IN
ANSWERS:
->
www.linuxquestions.org
internet address = 64.179.4.149
AUTHORITY RECORDS:
ADDITIONAL RECORDS:
------------
Non-authoritative answer:
Name:
www.linuxquestions.org
Address: 64.179.4.149
>
Are you getting INSTANT responses (try different lookups each time as once you've done a query the last response is probably sitting in the cache...).
Also try tracerouting your ISP's servers and pinging them.
I often have problems with Comcast's overworked, and buggy DNS servers in our area, which at times give slow resolution or timeouts.
I end up using another ISP's servers (in this case Speakeasy.net) so I merely place the Speakeasy server at the top of my /etc/resolv.conf file or specify this server in the interface configuration (see /etc/sysconfig/network-scripts/ifcfg-XXX ) so I don't have to type it in each time.
Not all ISP's will honor internet side queries, but you can try the above server which does. It's pretty fast for me.
Also consider installing a local caching nameserver (urpmi caching-nameserver) then edit the config file to add the above IP as a forwarder. That is, your machine will forward requests to the above site when it doesn't already know the answer. Each time it gets back an answer, it is held in it's cache, resulting in VERY VERY quick responses to domains you have already visited.