Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

This question already has an answer here:

I'm new about the config of the web server. I asked my hosting company to set the DNS to point to my VALID IP address, in the university. My server is ubuntu 12.04 (desktop). I installed apache2 and bind9. Now the ns ping points to my IP (, but when I ping my web site (, it points to its previous IP address ( I have included the file. Would you please help me. I want (and points to my IP address.

EDIT: I'm aware that it takes some time for IP addresses to be propagated, however, I can now ping and see the desired IP addressees, while the main address is not accessible. My question was about the difference between the way these names and IP addressees propagate.


; BIND data file for local loopback interface
$TTL    604800
@       IN      SOA (
                             35         ; Serial
                         604800         ; Refresh
                          86400         ; Retry
                        2419200         ; Expire
                         604800 )       ; Negative Cache TTL
;      IN      NS
@               IN      NS
@               IN      A
ns              IN      A
www             IN      CNAME
share|improve this question

marked as duplicate by HopelessN00b, Tim Brigham, Ward, mdpc, Katherine Villyard Mar 24 '14 at 20:20

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

It isn't names and IPs that propagate; it's DNS records of all types. – Falcon Momot Mar 25 '14 at 2:48
Would you please describe more. Do you mean my bind file is configures incorrectly? – remo Mar 26 '14 at 13:17
up vote 1 down vote accepted

DNS changes take time to "propagate," and you may have a DNS cache on your local machine (or for the local network) that's still pointing at the old address. I think the rule of thumb is to wait 72 hours for DNS changes to finish updating everywhere, assuming a standard DNS TTL setting (which DNS servers are free to ignore anyway).

share|improve this answer
If my config seems correct? I have seen some other such files with entries about emails, ftp, and ... . If it is necessary to put them within the file. – remo Mar 24 '14 at 10:54
@remo Looks fine to me, with the exception of your TTL being (probably) longer than you may want. Nothing you can do about that but change it and wait, though. As to other configs with entries for ftp and email, well, those would only apply if you have a host for ftp or mail (etc). If the only thing you have is the one website, then all you need is what you've got. – HopelessN00b Mar 24 '14 at 10:59
Thank you for your help. And finally, would you please introduce me a complete reference how to manage an ubuntu (web) server. a book is preferred please. – remo Mar 24 '14 at 11:10
@remo Sorry - I have no idea. Not a Ubuntu guy. – HopelessN00b Mar 24 '14 at 11:12

Have a look at your TTL : $TTL 604800

This indicates to all clients and caching nameservers how often it should check back with the authoritative nameserver for updated information. Here it is defined for 7 days.

Normally, if you plan to change your domains IP address, you should lower your TTL (24 hours) in advance, to allow the TTL change to fully propagate throughout the multiple DNS over the internet.

Also, caching nameservers will store the answer they get, and the Serial Number for the zone file. So, when you make any changes to your zone file, you should also increment the serial number.

share|improve this answer
I changed them to 86400, now. If I can check the IP of my website, tomorrow? – remo Mar 24 '14 at 11:03
Thank you for your suggestion. – remo Mar 24 '14 at 11:10
@remo Well, that will depend. Any DNS server that checked, say yesterday, and got a TTL of 7 days from now won't check back for several days, and will continue to cache the old address until it does. All you can really do it change the TTL, and wait until other DNS servers check back and get the updated record. – HopelessN00b Mar 24 '14 at 11:11

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