Sign up ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

I have a problem with my website ( and I have webmin and virualmin. I have one domain as alias, and this alias (host: sometimes is unavailable for several minutes. It's probably DNS problem because chrome shows 105 (net::ERR_NAME_NOT_RESOLVED).

How can I troubleshoot this problem?

What can cause that only sometimes website is unavailable for several minutes (DNS problem)?

share|improve this question
Can you give us the domain in question? – Nathan Adams Mar 9 '10 at 19:40

4 Answers 4

up vote 1 down vote accepted

First, ns1.visikid isn't found on the general internet:

tsavo:~ mcd$ host -t any
host: couldn't get address for '': not found

Your nameserver appears to be answering, but, has an SOA record that points to rather than

tsavo:~ mcd$ host -t any
Using domain server:
Aliases: mail is handled by 30 mail is handled by 30 mail is handled by 30 mail is handled by 10 mail is handled by 20 mail is handled by 20 mail is handled by 30 descriptive text "v=spf1 a mx ~all" has SOA record 1265887100 10800 3600 604800 38400 name server has address
tsavo:~ mcd$ host -t ns
Using domain server:
Aliases: name server

but, that domain isn't configured:

tsavo:~ mcd$ host
Host not found: 3(NXDOMAIN)

$ host
Using domain server:

Host not found: 5(REFUSED)

Adjust your SOA record on, or fix the ACL for if you're going to continue using it.

share|improve this answer
Thanks! Just add zone: $ttl 38400 IN SOA ( 1268245688 1200 3600 604800 38400 ) IN NS IN A IN A IN A – Kamil Rudnicki Mar 10 '10 at 19:11

You can use dig or nslookup (on windows) to a DNS lookup for your domain name:




If the name does not resolve to an IP, you might want to report his problem to your DNS provider.

share|improve this answer
Use "dig@dns_server" to query a specific DNS server. – John Gardeniers Mar 9 '10 at 3:04
This is a long and painful process. Better to use a tool which automates the most common tests like Zonecheck. – bortzmeyer Mar 12 '10 at 8:10

Cory has the right idea, but that will only query YOUR ISP's DNS servers, NOT the DNS server for your domain.

A couple of suggestions: Are you able to get to other websites while your website is having DNS issues? Find out all the DNS servers for your domain, and when you are having problems query each DNS server to find the one that isn't responding. If none of them are responding, yet you can still query other DNS servers, then you need to report this to your hoster.

share|improve this answer
Yes I'm able to get to other websites ( while my website is having DNS issues ( I have a BIND DNS server on my machine. It pretty strange problem... – Kamil Rudnicki Mar 9 '10 at 6:57

Using any DNS testing tool will show you your problems. The biggest: there is only one name server for If there is any problem with it (network, machine, whatever), the domain disappears.

This is the first fatal error reported by Zonecheck:

% zonecheck 
NS <= : []
NS    : []
NS    : []

~~~~ |    fatal    || ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
f> All addresses should be distinct
 | Adv: ZoneCheck
 |   To avoid losing all connectivity with the authoritative DNS in case
 | of network outage it is advised to host the DNS on different networks.
 | Ref: IETF RFC2182 (Abstract)
 |   The Domain Name System requires that multiple servers exist for every
 | delegated domain (zone). This document discusses the selection of
 | secondary servers for DNS zones. Both the physical and topological
 | location of each server are material considerations when selecting
 | secondary servers. The number of servers appropriate for a zone is also
 | discussed, and some general secondary server maintenance issues
 | considered.
 `----- -- -- - -  -
 :   The nameservers,,
 : are using the same IP address (
share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.