DNS debug with nslookup or dig

To test if the DNS of a domain is correct you may use nslookup (Mainly windows users) or dig (linux users).

From the windows command-prompt (Start > Run > cmd) (the black screen) you type:

nslookup

nslookup will wait for a servername or a record to be provided. Normally it has a > prompt.

Standardserver:  your.isp.hostname.ext
Address:  xxx.xxx.xx.x

> shqiperia.com
Server:  your.isp.hostname.ext
Address:  xxx.xxx.xx.x

Nicht autorisierte Antwort:
Name:    shqiperia.com
Address:  70.84.145.100

>

The nslookup queries the default DNS provided by the Internet Provider or set in the Network properties. If you would like to change to query for some other DNS (just to know if your domain is visible in Albania for example) you can change the DNS server to be queried.

Back in our office the Internet Provider is ABCOM with NS 80.78.66.66

> server 80.78.66.66
Standardserver:  [80.78.66.66]
Address:  80.78.66.66

So I set the server at 80.78.66.66 to answer my queries.

> shqiperia.com

Server:  [80.78.66.66]
Address:  80.78.66.66

Nicht autorisierte Antwort:
Name:    shqiperia.com
Address:  70.84.145.101

As seen the server is still pointing to an old IP and it will need some time for the cache to propogate.

Additionally there are different record types so I can instruct nslookup to provide result for specific records. The default query is of Type A DNS records.

I will alter it to query for the Nameservers.

> set type=NS
> shqiperia.com
Server:  [80.78.66.66]
Address:  80.78.66.66

Nicht autorisierte Antwort:
shqiperia.com   nameserver = ns1.shqiphost.com
shqiperia.com   nameserver = ns2.shqiphost.com
ns1.shqiphost.com       internet address = 70.84.145.98

If I want to know the record of the Mail Exchange for a specific domain:

> set type=MX
> shqiperia.com
Server:  [80.78.66.66]
Address:  80.78.66.66

Nicht autorisierte Antwort:
shqiperia.com   MX preference = 10, mail exchanger = mail.shqiperia.com

shqiperia.com   nameserver = ns1.shqiphost.com
mail.shqiperia.com      internet address = 212.117.184.4
ns1.shqiphost.com       internet address = 70.84.145.98

There are different type of records that can be queried. For more information check a Nslookup manual.

On the same way, the Linux users may use Dig to check their domain status.

Dig includes in one line the server to be queried and the record that you would like to query.

# dig @80.78.66.66 shqiperia.com MX

; <<>> DiG 9.3.4-P1 <<>> @80.78.66.66 shqiperia.com MX
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 47412
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2

;; QUESTION SECTION:
;shqiperia.com.                 IN      MX

;; ANSWER SECTION:
shqiperia.com.          86304   IN      MX      10 mail.shqiperia.com.

;; AUTHORITY SECTION:
shqiperia.com.          23416   IN      NS      ns1.shqiphost.com.

;; ADDITIONAL SECTION:
mail.shqiperia.com.     6636    IN      A       212.117.184.4
ns1.shqiphost.com.      83620   IN      A       70.84.145.98

;; Query time: 173 msec
;; SERVER: 80.78.66.66#53(80.78.66.66)
;; WHEN: Wed Aug 26 03:59:27 2009
;; MSG SIZE  rcvd: 112

OpenDNS Initiative has 2 public servers: 208.67.222.222 and 208.67.220.220. You can test how your DNS looks like in the world by quering those nameservers.

208.67.222.222 and 208.67.220.220

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