Client computers change DNS

[Atanaryon]

Hi all:
Last week changed my DC. Got a new machine running as DC, DHCP server
and DNS server.
Users can connect with no problem and get the right DNS servers I am
assigning them through DHCP.
Problem is suddenly (have detected no trigger for that) they change DNS
servers. Instead of .xxx and .yyy they've got .zzz, wich was the old
dns server.
Most strange of all, DHCP server is still the same in their computer.
Btw, both DHCP and DNS services have been uninstalled from old server.
Anyone can provide an idea about this?
Thanks in advance.

 

[Herb Martin]

Hi all:
Last week changed my DC. Got a new machine running as DC, DHCP server
and DNS server.
Users can connect with no problem and get the right DNS servers I am
assigning them through DHCP.
Problem is suddenly (have detected no trigger for that) they change DNS
servers. Instead of .xxx and .yyy they've got .zzz, wich was the old
dns server.

Show us your UNEDITED, TEXT from "IPConfig /all >name.txt"

If you use DHCP but ALSO set the clients on their NIC to override
the DNS then you get the manual client setting.

IPConfig /all always shows the CURRENT settings -- no matter how
they got that way though.

 

[Kevin D. Goodknecht Sr. [MVP]]

Hi all:
Last week changed my DC. Got a new machine running as DC, DHCP server
and DNS server.
Users can connect with no problem and get the right DNS servers I am
assigning them through DHCP.
Problem is suddenly (have detected no trigger for that) they change
DNS servers. Instead of .xxx and .yyy they've got .zzz, wich was the
old dns server.
Most strange of all, DHCP server is still the same in their computer.
Btw, both DHCP and DNS services have been uninstalled from old server.
Anyone can provide an idea about this?
Thanks in advance.

Check your Group Policy here:
Computer Configuration
-Administrative templates
-Network
-DNS Client

--
Best regards,
Kevin D. Goodknecht Sr. [MVP]
Hope This Helps
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[Atanaryon]

Thanks for both answers.
We have no manual nic configuration.
Also, we have no group policy applied to any machine.
Strange thing is that when clients connect, everything works fine and
DNS are right. It's some time later (with no specific reason) that DNS
server is changed.
Will keep looking for an answer.

 

[Herb Martin]

Thanks for both answers.
We have no manual nic configuration.
Also, we have no group policy applied to any machine.
Strange thing is that when clients connect, everything works fine and
DNS are right. It's some time later (with no specific reason) that DNS
server is changed.
Will keep looking for an answer.

You didn't show use your IPConfig /all info.

Usually we can find the problem fairly fast.

 

[Atanaryon]

Here you have both IPconfigs.
First one is the BAD situation. When suddenly connections start to fail
and DNS doesn't work.

Configuración IP de Windows
Nombre del host . . . . . . . . . : sp-aesmarats
Sufijo DNS principal . . . . . . : SSLBARCELONA.ICO
Tipo de nodo. . . . . . . . . . . : híbrido
Enrutamiento habilitado. . . . . .: No
Proxy WINS habilitado. . . . . : No
Lista de búsqueda de sufijo DNS: SSLBARCELONA.ICO
SSLBARCELONA.ICO

Adaptador Ethernet Conexión de área local :
Sufijo de conexión específica DNS : SSLBARCELONA.ICO
Descripción. . . . . . . . . . . : Broadcom NetXtreme Gigabit
Ethernet for hp
Dirección física. . . . . . . . . : 00-0D-9D-D1-77-C1
DHCP habilitado. . . . . . . . . : No
Autoconfiguración habilitada. . . : Sí
Dirección IP. . . . . . . . . . . : 172.20.104.65
Máscara de subred . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada : 172.20.104.2
Servidor DHCP . . . . . . . . . . : 172.20.104.249
Servidores DNS . . . . . . . . . .: 172.20.104.250
Concesión obtenida . . . . . . . : jueves, 25 de enero de
2007 8:52:24
Concesión expira . . . . . . . . .: sábado, 27 de enero de
2007 8:52:24


And second one is the GOOD situation, after simply doing a renew. If
you restart the machine you get this same information, the one we send
with the dhcp.

Configuración IP de Windows
Nombre del host . . . . . . . . . : sp-aesmarats
Sufijo DNS principal . . . . . . : SSLBARCELONA.ICO
Tipo de nodo. . . . . . . . . . . : híbrido
Enrutamiento habilitado. . . . . .: No
Proxy WINS habilitado. . . . . : No
Lista de búsqueda de sufijo DNS: SSLBARCELONA.ICO
SSLBARCELONA.ICO

Adaptador Ethernet Conexión de área local :
Sufijo de conexión específica DNS : SSLBARCELONA.ICO
Descripción. . . . . . . . . . . : Broadcom NetXtreme Gigabit
Ethernet for hp
Dirección física. . . . . . . . . : 00-0D-9D-D1-77-C1
DHCP habilitado. . . . . . . . . : No
Autoconfiguración habilitada. . . : Sí
Dirección IP. . . . . . . . . . . : 172.20.104.65
Máscara de subred . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada : 172.20.104.2
Servidor DHCP . . . . . . . . . . : 172.20.104.249
Servidores DNS . . . . . . . . . .: 172.20.104.249
172.16.128.133
Concesión obtenida . . . . . . . : jueves, 25 de enero de
2007 11:37:58
Concesión expira . . . . . . . . .: jueves, 01 de febrero de
2007 11:37:58

As you can see, DHCP is the same in both cases, and it's the right DHCP
server. What we don't understand is how the dns info is suddenly lost.
If you need any translation let me know.
Thanks for your cooperation:
Daniel.

 

[Herb Martin]

Here you have both IPconfigs.

First one is the BAD situation.

Nombre del host . . . . . . . . . : sp-aesmarats (BAD)
Dirección IP. . . . . . . . . . . : 172.20.104.65
Servidor DHCP . . . . . . . . . . : 172.20.104.249
Servidores DNS . . . . . . . . . .: 172.20.104.250

second one is the GOOD situation

Dirección IP. . . . . . . . . . . : 172.20.104.65
Servidor DHCP . . . . . . . . . . : 172.20.104.249
Servidores DNS . . . . . . . . . .: 172.20.104.249
172.16.128.133

As you can see, DHCP is the same in both cases, and it's the right DHCP
server. What we don't understand is how the dns info is suddenly lost.

Ok, the "DNS info" is not technically "LOST" but rather different, or being
replaced.

This will only happen one of two ways:

1) Different DHCP settings (usually from a different DHCP server, but
technically there are other ways) None of this seems to apply
here.

2) Clients actual settings on the NIC->IP properties

Check the NIC for this client. Any value in the NIC->IP -> DNS server
will OVERRIDE the DHCP settings but this should be 100% of the time.

One odd possibility: The client is set with an ALTERNATE IP (for when the
DHCP server is unavailable) but this shouldn't apply either since in that
case
the DHCP server should not be listed when using the ALTERNATE config.
(Also on the NIC->IP dialog->Alternate tab.)

I trust your report (now that I have seen the IPconfigs <grin>) so this does
have a strong possibility of being some weird bug in the OS. What is the
version and service pack status of both the DHCP server and the problem
clients? (Spanish language OS probably, not just the MUI I expect.)

None of that should account for this though.

If none of this works, look carefully at the DHCP scope(s). Theorectically
you could have TWO SCOPE for the same subnet (on the same server),
somehow superscoped (i.e., grouped into one scope) and with OVERLAPPING
addresses so that they assign different DNS servers....

This may not be literally possible, and of course I have NEVER tried to
actual
do that last part (overlap multinet scopes makes no sense) but it is close
to the
only (non-bug) way I can imagine this happening -- so far.

If you need any translation let me know.

No, I read Spanish passably. <grin> I read all of the Harry Potter novels
in
Spanish, and the Davinci Code, last year to teach myself Spanish. I don't
speak or write it very well though.

 

[Kevin D. Goodknecht Sr. [MVP]]

Here you have both IPconfigs.
First one is the BAD situation. When suddenly connections start to
fail
and DNS doesn't work.

Configuración IP de Windows
Nombre del host . . . . . . . . . : sp-aesmarats
Sufijo DNS principal . . . . . . : SSLBARCELONA.ICO
Tipo de nodo. . . . . . . . . . . : híbrido
Enrutamiento habilitado. . . . . .: No
Proxy WINS habilitado. . . . . : No
Lista de búsqueda de sufijo DNS: SSLBARCELONA.ICO
SSLBARCELONA.ICO

Adaptador Ethernet Conexión de área local :
Sufijo de conexión específica DNS : SSLBARCELONA.ICO
Descripción. . . . . . . . . . . : Broadcom NetXtreme Gigabit
Ethernet for hp
Dirección física. . . . . . . . . : 00-0D-9D-D1-77-C1
DHCP habilitado. . . . . . . . . : No
Autoconfiguración habilitada. . . : Sí
Dirección IP. . . . . . . . . . . : 172.20.104.65
Máscara de subred . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada : 172.20.104.2
Servidor DHCP . . . . . . . . . . : 172.20.104.249
Servidores DNS . . . . . . . . . .: 172.20.104.250
Concesión obtenida . . . . . . . : jueves, 25 de enero de
2007 8:52:24
Concesión expira . . . . . . . . .: sábado, 27 de enero de
2007 8:52:24


And second one is the GOOD situation, after simply doing a renew. If
you restart the machine you get this same information, the one we send
with the dhcp.

Configuración IP de Windows
Nombre del host . . . . . . . . . : sp-aesmarats
Sufijo DNS principal . . . . . . : SSLBARCELONA.ICO
Tipo de nodo. . . . . . . . . . . : híbrido
Enrutamiento habilitado. . . . . .: No
Proxy WINS habilitado. . . . . : No
Lista de búsqueda de sufijo DNS: SSLBARCELONA.ICO
SSLBARCELONA.ICO

Adaptador Ethernet Conexión de área local :
Sufijo de conexión específica DNS : SSLBARCELONA.ICO
Descripción. . . . . . . . . . . : Broadcom NetXtreme Gigabit
Ethernet for hp
Dirección física. . . . . . . . . : 00-0D-9D-D1-77-C1
DHCP habilitado. . . . . . . . . : No
Autoconfiguración habilitada. . . : Sí
Dirección IP. . . . . . . . . . . : 172.20.104.65
Máscara de subred . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada : 172.20.104.2
Servidor DHCP . . . . . . . . . . : 172.20.104.249
Servidores DNS . . . . . . . . . .: 172.20.104.249
172.16.128.133
Concesión obtenida . . . . . . . : jueves, 25 de enero de
2007 11:37:58
Concesión expira . . . . . . . . .: jueves, 01 de febrero de
2007 11:37:58

As you can see, DHCP is the same in both cases, and it's the right
DHCP
server. What we don't understand is how the dns info is suddenly lost.
If you need any translation let me know.
Thanks for your cooperation:

I also see that the NICs are using Autoconfiguration, not DHCP.

DHCP habilitado. . . . . . . . . : No
Autoconfiguración habilitada. . . : Sí

--
Best regards,
Kevin D. Goodknecht Sr. [MVP]
Hope This Helps
Send IM: http://www.icq.com/people/webmsg.php?to=296095728
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It will strip signature out and more
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