DHCP Server has wrong interface address

In troubleshooting an nslookup problem with one of my clients, I have found
that DHCP has the server name associated with the external IP address.

The internal subnet is 192.168.10.x and the external is 192.168.77.x (both
with /24 subnet masks). Last night I deactivated then deleted the scope,
unauthorized then deleted the server, and went through the setup wizard to
recreate everything using the internal ip address (192.168.10.40) for the
server.

This morning I check it and once again the server name is
"server.mylan.local[192.168.77.240]" and the scope name is
"Scope[192.168.10.0]mylan.local.scope".

Any idea of why DHCP would change the server name to reflect the external
NIC? Whenever I try to do an nslookup by host name, it tries to resolve
using the external DNS and fails with can't find mypc: Non-existent domain.
It seems like the two problems are related.

Any help is greatly appreciated!
--
IT Consultant
Heartland Computer

"chaswood" wrote:
> In troubleshooting an nslookup problem with one of my clients, I have found
> that DHCP has the server name associated with the external IP address.
>
> The internal subnet is 192.168.10.x and the external is 192.168.77.x (both
> with /24 subnet masks). Last night I deactivated then deleted the scope,
> unauthorized then deleted the server, and went through the setup wizard to
> recreate everything using the internal ip address (192.168.10.40) for the
> server.
>
> This morning I check it and once again the server name is
> "server.mylan.local[192.168.77.240]" and the scope name is
> "Scope[192.168.10.0]mylan.local.scope".

Probably you see your server's name associated with the external IP address
because it makes a query on your DNS server asking which IP is associated to
"server.mylan.local". This could be the last of your problems but, if you
don't want your DHCP server to register the external IP address you can
change its TCP/IP configuration: right click "My Network Places" and select
Properties; right click the external NIC and select Properties; from
"Internet Protocol TCP/IP" properties select Advanced; in the DNS tab
de-select "Register this connection's addresses in DNS". After this, unless
you have configured Aging/Scavenging in your DNS server, you should probably
delete the external NIC's record.

>
> Any idea of why DHCP would change the server name to reflect the external
> NIC? Whenever I try to do an nslookup by host name, it tries to resolve
> using the external DNS and fails with can't find mypc: Non-existent domain.
> It seems like the two problems are related.

Have you correctly configured TCP/IP DNS parameters of your DHCP server?
Have you added "006 DNS servers" scope option pointing to your internal DNS
server(s)? If you run "nslookup server.mylan.local" (where I suppose
server.mylan.local is your DHCP server's FQDN) from your DHCP server, what
does the DNS server answer to you?

>
> Any help is greatly appreciated!
> --
> IT Consultant
> Heartland Computer

Hope it helps.

Regards,

Carlo

Thank you Carlo. The bindings under advanced properties are correctly set to
only the internal nic (192.168.10.40). The scope options are all set to the
internal NIC.

003 Router 192.168.10.40
044 WINS/NBT Node Type 192.168.10.40
006 DNS Server 192.168.10.40
015 DNS Domain Name boiler.local

Yet here is the result of nslookup:

C:\Documents and Settings\Administrator>nslookup server1.boiler.local
Server: ns1.ispprovt.net
Address: 209.246.180.200

*** ns1.iquest.net can't find server1.boiler.local: Non-existent domain

The query is not resolved by DNS on my client's server, instead it only goes
to the ISP's DNS server.

DNS on my client's server has the correct host record for server1
(192.168.10.40).

Again, all help is appreciated.

--
IT Consultant
Heartland Computer


"Carlo Cacciafesta" wrote:

> "chaswood" wrote:
> > In troubleshooting an nslookup problem with one of my clients, I have found
> > that DHCP has the server name associated with the external IP address.
> >
> > The internal subnet is 192.168.10.x and the external is 192.168.77.x (both
> > with /24 subnet masks). Last night I deactivated then deleted the scope,
> > unauthorized then deleted the server, and went through the setup wizard to
> > recreate everything using the internal ip address (192.168.10.40) for the
> > server.
> >
> > This morning I check it and once again the server name is
> > "server.mylan.local[192.168.77.240]" and the scope name is
> > "Scope[192.168.10.0]mylan.local.scope".
>
> Probably you see your server's name associated with the external IP address
> because it makes a query on your DNS server asking which IP is associated to
> "server.mylan.local". This could be the last of your problems but, if you
> don't want your DHCP server to register the external IP address you can
> change its TCP/IP configuration: right click "My Network Places" and select
> Properties; right click the external NIC and select Properties; from
> "Internet Protocol TCP/IP" properties select Advanced; in the DNS tab
> de-select "Register this connection's addresses in DNS". After this, unless
> you have configured Aging/Scavenging in your DNS server, you should probably
> delete the external NIC's record.
>
> >
> > Any idea of why DHCP would change the server name to reflect the external
> > NIC? Whenever I try to do an nslookup by host name, it tries to resolve
> > using the external DNS and fails with can't find mypc: Non-existent domain.
> > It seems like the two problems are related.
>
> Have you correctly configured TCP/IP DNS parameters of your DHCP server?
> Have you added "006 DNS servers" scope option pointing to your internal DNS
> server(s)? If you run "nslookup server.mylan.local" (where I suppose
> server.mylan.local is your DHCP server's FQDN) from your DHCP server, what
> does the DNS server answer to you?
>
> >
> > Any help is greatly appreciated!
> > --
> > IT Consultant
> > Heartland Computer
>
> Hope it helps.
>
> Regards,
>
> Carlo

"chaswood" wrote:
> Thank you Carlo. The bindings under advanced properties are correctly set to
> only the internal nic (192.168.10.40). The scope options are all set to the
> internal NIC.
>
> 003 Router 192.168.10.40
> 044 WINS/NBT Node Type 192.168.10.40
> 006 DNS Server 192.168.10.40
> 015 DNS Domain Name boiler.local
>
> Yet here is the result of nslookup:
>
> C:\Documents and Settings\Administrator>nslookup server1.boiler.local
> Server: ns1.ispprovt.net
> Address: 209.246.180.200
>
> *** ns1.iquest.net can't find server1.boiler.local: Non-existent domain
>
> The query is not resolved by DNS on my client's server, instead it only goes
> to the ISP's DNS server.
>
> DNS on my client's server has the correct host record for server1
> (192.168.10.40).
>
> Again, all help is appreciated.
>
> --
> IT Consultant
> Heartland Computer

I really can't imagine what the cause of your problem could be but we can
try to troubleshoot.

So, if you run "nslookup server1.boiler.local" from anyone of your clients
(including your server) you receive an answer for your ISP's DNS
(ns1.ispprovt.net). If you run "ipconfig /all" on one random client, is "DNS
Server . . . 192.168.10.40"? If so you can try to set TCP/IP configuration
manually on that client, run "ipconfig /flushdns", then run nslookup again.
If the query is answered from the ISP's DNS again we can go on investigating
on the DNS server.

What happens is strange since, if your DNS server hosts the zone
"boiler.local", it should never forward the query to another server; if it
hosts the zone and a record you query for doesn't exist (that is not your
case) it should answer without using recursion. Are there any errors in the
DNS events?

Let me know and we'll try to solve the problem.

Regards,

Carlo