fuzzyfreak
asked on
DNS cache issue? Internal network pointing to old web server, ok for outside.
We recently updated our website and changed our website server. DNS has been updated so the outside World can see our new website. Internally, within our Windows domain, all resolves are still going to the old IP.
On our DNS server, I tried scavenging stale resources records and clearing the cache and even looked for a forwarder which might be doing this. I then checked our Firewall and updated one address object with the new IP but still, the server and so the clients point to the old IP. Does anybody have any light bulbs on this issue?
On our DNS server, I tried scavenging stale resources records and clearing the cache and even looked for a forwarder which might be doing this. I then checked our Firewall and updated one address object with the new IP but still, the server and so the clients point to the old IP. Does anybody have any light bulbs on this issue?
ASKER
Yes, I am already at that stage. Which is why I need help troubleshooting the DNS server - it is this that is giving out the wrong IP.
So you have FULL control over this DNS server? Does it really serve its own DNS entries, or only acts as a forwarder?
If it is really a DNS server (of course, partially forwarding unknown entries), then find the domain.com (just an example!) in the Forward Lookup zones tree structure, and check if there's a www A record entry. Adjust IP address if there is.
If it is really a DNS server (of course, partially forwarding unknown entries), then find the domain.com (just an example!) in the Forward Lookup zones tree structure, and check if there's a www A record entry. Adjust IP address if there is.
ASKER
Hi, yes, I have full control over the DNS server, yes it serves internal DNS requests. My domain name is different from the domain of the site, which is why I looked for a forwarder already and I can't see one. I am pretty sure you are on the right track though, can you search DNS for an IP address entry?
No, you can't find it by searching for an IP address (would be a nice feature though!). You have to find it like this, If the webserver is:
server1.www.domain.com
there HAS to be a forward zone either:
server1.www.domain.com (with plain A record)
or
www.domain.com (with A record for server1)
or
domain.com (with subtree www, AND A record for server1 under here)
If you are SURE it's not there, on this server, also do an NSlookup, but have it query the forwarding DNS. If it returns the old IP address, ask them to update it, or just add it to your DNS server as a new entry. Just make sure other DNS entries won't interfere. Make an entry for the server1.www.domain.com zone with the IP address as an A record for the parent, instead of domain.com and sub entries. The reason is that server2.www.domain will still resolve correctly without interference using the first method, while it will not return an IP address anymore if you use the second method.
server1.www.domain.com
there HAS to be a forward zone either:
server1.www.domain.com (with plain A record)
or
www.domain.com (with A record for server1)
or
domain.com (with subtree www, AND A record for server1 under here)
If you are SURE it's not there, on this server, also do an NSlookup, but have it query the forwarding DNS. If it returns the old IP address, ask them to update it, or just add it to your DNS server as a new entry. Just make sure other DNS entries won't interfere. Make an entry for the server1.www.domain.com zone with the IP address as an A record for the parent, instead of domain.com and sub entries. The reason is that server2.www.domain will still resolve correctly without interference using the first method, while it will not return an IP address anymore if you use the second method.
ASKER
It is definitely not there.
How do I make nslookup query the forwarding DNS?
Ask them to update it?
Forgive me but I am little lost with the instructions that follow about making an entry. Do I right click my DNS server...which option am I selecting here?
I am afraid I do not understand the reasoning you describe.
Many thanks.
How do I make nslookup query the forwarding DNS?
Ask them to update it?
Forgive me but I am little lost with the instructions that follow about making an entry. Do I right click my DNS server...which option am I selecting here?
I am afraid I do not understand the reasoning you describe.
Many thanks.
also check the Hosts file c:\windows\system32\driver
ASKER
Nothing in the host file.
Is there an A record in your internal DNS - does it point to the webserver ? There is NO enrty in the Hosts file (thats good)
If there is NO A record in your internal DNS then the DNS server will ask the external DNS servers for the Address.
BTW on your client is there only one DNS as primary or is there a scundairy DNS ?
If there is NO A record in your internal DNS then the DNS server will ask the external DNS servers for the Address.
BTW on your client is there only one DNS as primary or is there a scundairy DNS ?
First find out who is the forwarding DNS server (it's in the properties of your DNS server)
Open a cmd box (Start > Run > cmd (enter) >
nslookup (enter)
server IP_nr_forwarding_dns (enter)
www.domain.com (the actual web server, enter)
Most probably that will return the old IP, as it's not possible that you don't host this record, and the forwarding DNS also doesn't host it. It's either you or the forwarding DNS.
Then try to find out who owns this DNS server (most probably your ISP, so call them and ask them to update).
Or forget about trying to find out, and just add a www.domain.com zone with the appropiate parent A record.
Open a cmd box (Start > Run > cmd (enter) >
nslookup (enter)
server IP_nr_forwarding_dns (enter)
www.domain.com (the actual web server, enter)
Most probably that will return the old IP, as it's not possible that you don't host this record, and the forwarding DNS also doesn't host it. It's either you or the forwarding DNS.
Then try to find out who owns this DNS server (most probably your ISP, so call them and ask them to update).
Or forget about trying to find out, and just add a www.domain.com zone with the appropiate parent A record.
ASKER
Aha, we are getting somewhere, it seems one of our ISPs DNS servers has not updated.
Thanks!
Thanks!
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ASKER
Thanks for all your help. I was being impatient, our ISPs DNS needed 24hrs to update.
Hope your issue is now resolved !
ipconfig /flushdns
then do a nslookup to your new website. Please note the result AND the responding DNS server. If the result is wrong, something is wrong at the queried server. Start investigating this server first (and then after that maybe something is wrong with the forwarding server).