Offline Offline
Posts: 652
View Profile Personal Message (Offline)
DNS/nameserver tool for admins, webmasters and people with DNS problems
« on: May 07, 2008, 10:23:53 AM »
Reply with quoteQuote
Not many people know, but it is quite easy to diagnose DNS problems. It can (will) save you a lot of time searching for problems doing that more efficient. The domain doctor already is for that, but apparently that is not enough, so some tips here about diagnosing;
Use dig.
That's it Smiley
For all *sigh* Windows users;
http://members.shaw.ca/nicholas.fong/dig/For Linux users; install dnsutils and you'll have it (Ubuntu/Debian; apt-get install dnsutils).
For ease of use;
http://www.110mb.com/dig.phpfor instance;
http://www.110mb.com/dig.php?url=thefacepaintinglady.co.ukNot that ns4 does *not* respond to extra domains; that is intentional ; it is meant as a backup for 110mb.com and 911mb.com. Don't use it for extra domains.
Some explaining of the result;
First result is A records, which is
dig domain.com
Look for;
;; ANSWER SECTION:
thefacepaintinglady.co.uk. 85711 IN A 195.242.99.182
the IP behind the A should be one of our boxes. If there are no A or empty A, something is very wrong, but before blaming us, read on;
The second is the NS;
dig NS domain.com
Look for;
;; AUTHORITY SECTION:
thefacepaintinglady.co.uk. 85711 IN NS ns2.110mb.com.
thefacepaintinglady.co.uk. 85711 IN NS ns1.110mb.com.
Extra domains should contain NS ns1 and NS ns2 in this region, native domains (ie username.110mb.com) should contain NS n1, NS ns2, NS ns3, NS ns4.
The next section queries all our nameservers for your domain;
dig @ns1.110mb.com domain.com
dig @ns2.110mb.com domain.com
dig @ns3.110mb.com domain.com
dig @ns4.110mb.com domain.com
Look for;
;; ANSWER SECTION:
thefacepaintinglady.co.uk. 86400 IN A 195.242.99.182
The IP behind the A should be the same for all 4 nameservers. Note that ns4 will not respond for extra domains; that is fine.
Now;
- if the IP is different in the nameservers in the last 4 tests; wait 24 hours
- if the first test does not return an A record with an IP
- - if the second test does not answer with at least NS ns1, NS ns2 ; your domain DNS settings are wrong; fix them
- - any other problem; wait 24 hours then contact an admin here
- if the first test returns the wrong IP
- - the last 4 tests are returning the right; wait 24 hours
- - the second test has the wrong nameservers (no NS ns1, NS ns2) ; your domain DNS settings are wrong; fix them