What could cause this?-Nameservers

[Rommeo]

I have changed the name servers of one of my domain names.

Nowadays I need to use the internet of a university here, inside the university I m not able to reach my website with new settings, it still shows the page that is available in old hosting. Outside the university, where ever I go I m able to reach my website with its new hosting and settings. I have also asked my friends in other countries, they are also able to see the website with its new settings. But inside the university still old page.. what can cause this?

[Stooney]

DNS caching.  Whichever DNS server you're using while on the university's connection hasn't gotten the update yet.  Try setting your primary DNS server on your computer to one of Google's (75.75.75.75) and see what happens.  Also flush your DNS cache: open the command prompt and type: ipconfig /flushdns

[Rommeo]

Wondering if this update is up to university staff? I mean 2 days have passed and it's so long time for this kind of update. It took 2 hours for my friends in EU. There is a big gap between 2 hours and 2 days..

 

and unfortunately they say university forbid to use other DNS servers.

[Rommeo]

any ideas? I m wondering if this update is up to staff? or there is a program installed to those servers and it automatically updates itself?

[kicken]

Use tools like dig (linux) or nslookup (windows) to debug what nameservers your using and how long they have the domain cached for.

 

For example:

Using NSLookup

C:\Users\Keith>nslookup -type=A -debug yourdomain.com.
Server:  google-public-dns-a.google.com
Address:  8.8.8.8

------------
Got answer:
    HEADER:
        opcode = QUERY, id = 2, rcode = NOERROR
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 1,  authority records = 0,  additional = 0

    QUESTIONS:
        yourdomain.com, type = A, class = IN
    ANSWERS:
    ->  yourdomain.com
        internet address = 173.230.139.100
        ttl = 3128 (52 mins 8 secs)

------------
Non-authoritative answer:
Name:    yourdomain.com
Address:  XXX.XXX.139.100

 

The lines of interest above are the Server: and Address: lines which tell you what dns server (name and ip) your using and the ttl = line which tells you how long the given result will remain in cache.

 

Using dig

kicken@linode:~$ dig yourdomain.com. A

; <<>> DiG 9.7.3 <<>> yourdomain.com. A
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22037
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0

;; QUESTION SECTION:
;yourdomain.com.               IN      A

;; ANSWER SECTION:
yourdomain.com.        3600    IN      A       XXX.XXX.139.100

;; AUTHORITY SECTION:
yourdomain.com.        3600    IN      NS      ns54.domaincontrol.com.
yourdomain.com.        3600    IN      NS      ns53.domaincontrol.com.

;; Query time: 65 msec
;; SERVER: 75.127.97.6#53(75.127.97.6)
;; WHEN: Sat Jul 28 01:17:35 2012
;; MSG SIZE  rcvd: 104

 

The lines of interest there is the one below ;;ANSWER SECTION and the one starting ;; SERVER.  The number shown in the answer section after the domain (3600 above) is the TTL showing how long the entry is in cache for.  The ;; SERVER line is what dns server (name/ip) your using.

 

Once you find out the TTL time for the domain, wait until it should have expired and try the lookups again.  If your still getting the wrong results, you'll probably have to contact the network admins and have them investigate what the issue may be.