Name resolution issues.

[Gino Castoldi_2]

Hi,

Server: W2K3 SP1

We have a server that is not in DNS.
I added the hostname/ip to the local "hosts" file. I also updated the name resolution order priority in the registry of the server that is doing host name lookups.

When I run 'nslookup' it only works for resolving the ip address -> FQDN. When I try the reverse lookup it fails (short hostname or FQDN -> ip address).

Does anyone have any ideas as to why the hostname resolution is not work properly?

10 points to any good answer.
Gino

[Igor Karasik · Accepted solution]

Gino,
Just to clarify:
1) Is "ping -a IP address" work ?
2) You write "updated the name resolution order priority in the registry". But I think windows default name resolution order is
-hosts file
-DNS
-NetBIOS
So hosts file by default first - what exactly you change in the registry?
Also, reverse lookup (ptr) is "IP address -> FQDN" and according your post reverse lookup work. Only "FQDN -> IP address" doesn't work in your case - right?

[Ivan Ferreira]

I'm not 100% sure, but I think that nslookup does not use the hosts file for resultion, it consults the DNS server directly. Check the name resolution with ping.

[Gino Castoldi_2]

Hi,

1) Is "ping -a IP address" work ?
Yes, I am able to ping the server.

2) You write "updated the name resolution order priority in the registry".
So hosts file by default first - what exactly you change in the registry?
Here is order I changed it to:
1.LocalCache
2. hosts file
3. DNS
4. NetBIOS

>Also, reverse lookup (ptr) is "IP address -> FQDN" and according your post reverse lookup work. Only "FQDN -> IP address" doesn't work in your case - right?
Right.

>I'm not 100% sure, but I think that nslookup does not use the hosts file for resultion, it consults the DNS server directly. Check the name resolution with ping.
Pinging the server does work. Is there a way
have it use the "hosts" file first instead of DNS?

10 points to any good answer.
Thank you, Gino

[Ivan Ferreira]

Pinging the server does work. Is there a way
have it use the "hosts" file first instead of DNS?


You cannot use nslookup to test name resolution with hosts file. See:

http://www.microsoft.com/resources/documentation/Windows/XP/all/reskit/en-us/Default.asp?url=/resources/documentation/Windows/XP/all/reskit/en-us/prjj_ipa_tyjo.asp

What I don't understand is why if the "ping hostname" command works, what is the problem that you currently have? That is your name resolution test.

Why don't you use DNS? You can configure a DNS zone only for private computers.

[Pieter 't Hart]

first let's use the same keywords
query a host by to find it's ip-adress is called forward lookup and ip-adres -> hostname is reverse lookup.

first check the network settings " ipconfig /all"
What DNS's are configured
what domain-extension is configured

seccond check the DNS
- does it alow "dynamic updates"
- does it have an entry for this host in the right zone
in the named forwardl lookup zone there must be an antry wich assigns the name to the ip-adres. by cheking the "update PTR-record", also the reverse lookup entry will be updated.

check the eventlog of the server
any DNS-related entries (cannot register...)
check the eventlog of the DNS (duplicate...)

maybe yo want to clear the evenlog first and reboot to isolate recent events from older

Pieter

[Mike Strako]

Host files do work on the local server assuming your using that local box to broadcast, other servers will also need the same host file. After that, you should be all set.