Unwanted DNS Server

sprautzpng · 06-28-2009, 08:26 PM

I have a network, all the clients are served Ip address from the DHCP. The DNS is automatically pushed to the clients. However, when I check the network icon and visited the Support, Details a completely different DNS server is listed, one that does not fit into the address scheme of my network.

I can manually enter the address of the DNS serveron the client machine, but this not what I want, I want the client the automatically pick the right DNS server address.

What could be thr problem, please help.

sprautzpng

**Squashman** · 06-28-2009, 08:54 PM

The client computers can only get their DNS settings one of two ways.
Automatically during a DHCP request or they are manually set in the Network properties.
Only other thing I can think of would be a rogue DHCP server on your network.

**Squashman** · 06-28-2009, 08:55 PM

The client computers can only get their DNS settings one of two ways.
Automatically during a DHCP request or they are manually set in the Network properties.
Only other thing I can think of would be a rogue DHCP server on your network.

sprautzpng · 06-29-2009, 12:43 AM

Thank you,
But,
1. How do I identify the rogue DNS Server?
2. How do I ensure that the authorised DNS are the only ones the Clients commincate with?

sprautzpng

**bilbus** · 06-29-2009, 01:09 PM

if you are using dhcp and all the other information is correct, then its your fault, fix the dns in your dhcp console.

If they are getting ip information from dhcp thats not correct (or within the scope that you setup) then you have a rogue dhcp server.

sprautzpng · 06-30-2009, 10:16 PM

Thanks,

I have checked my DCP server and it is pointing to the right DNS server.

So what then would be the problem?

**bilbus** · 06-30-2009, 10:19 PM

look on the client, run ipconfig /all

look for "dhcp server" it will have an ip address, that client is getting its settings from that ip address.

if thats a known server... say a old one you no longer use remove it. if its not a managed computer you will need to locate it and remove it from the network (rogue)

sprautzpng · 07-02-2009, 12:23 AM

Bilbus,

Thankyou I have identified a possible problem. Did work on it and am just monitoring the system.

If the problem still persist, I will sound out an SOS again.

Thanks
sprautzpng

**bilbus** · 07-02-2009, 05:42 AM

What was the cause?

06-28-2009, 08:26 PM	#1 (permalink)
sprautzpng Registered User Join Date: Oct 2008 Posts: 14 OS: XP	Unwanted DNS Server I have a network, all the clients are served Ip address from the DHCP. The DNS is automatically pushed to the clients. However, when I check the network icon and visited the Support, Details a completely different DNS server is listed, one that does not fit into the address scheme of my network. I can manually enter the address of the DNS serveron the client machine, but this not what I want, I want the client the automatically pick the right DNS server address. What could be thr problem, please help. sprautzpng

06-28-2009, 08:54 PM	#2 (permalink)
Squashman Tech, Networking Forums Join Date: Apr 2005 Location: 1265 Lombardi Ave. Posts: 1,142 OS: All of the above	Re: Unwanted DNS Server The client computers can only get their DNS settings one of two ways. Automatically during a DHCP request or they are manually set in the Network properties. Only other thing I can think of would be a rogue DHCP server on your network.

06-28-2009, 08:55 PM	#3 (permalink)
Squashman Tech, Networking Forums Join Date: Apr 2005 Location: 1265 Lombardi Ave. Posts: 1,142 OS: All of the above	Re: Unwanted DNS Server The client computers can only get their DNS settings one of two ways. Automatically during a DHCP request or they are manually set in the Network properties. Only other thing I can think of would be a rogue DHCP server on your network.

06-29-2009, 12:43 AM	#4 (permalink)
sprautzpng Registered User Join Date: Oct 2008 Posts: 14 OS: XP	Re: Unwanted DNS Server Thank you, But, 1. How do I identify the rogue DNS Server? 2. How do I ensure that the authorised DNS are the only ones the Clients commincate with? sprautzpng

06-29-2009, 01:09 PM	#5 (permalink)
bilbus TSF Enthusiast Join Date: Aug 2006 Posts: 950 OS: OS2 Warp	Re: Unwanted DNS Server if you are using dhcp and all the other information is correct, then its your fault, fix the dns in your dhcp console. If they are getting ip information from dhcp thats not correct (or within the scope that you setup) then you have a rogue dhcp server.

06-30-2009, 10:16 PM	#6 (permalink)
sprautzpng Registered User Join Date: Oct 2008 Posts: 14 OS: XP	Re: Unwanted DNS Server Thanks, I have checked my DCP server and it is pointing to the right DNS server. So what then would be the problem?

06-30-2009, 10:19 PM	#7 (permalink)
bilbus TSF Enthusiast Join Date: Aug 2006 Posts: 950 OS: OS2 Warp	Re: Unwanted DNS Server look on the client, run ipconfig /all look for "dhcp server" it will have an ip address, that client is getting its settings from that ip address. if thats a known server... say a old one you no longer use remove it. if its not a managed computer you will need to locate it and remove it from the network (rogue)

07-02-2009, 12:23 AM	#8 (permalink)
sprautzpng Registered User Join Date: Oct 2008 Posts: 14 OS: XP	Re: Unwanted DNS Server Bilbus, Thankyou I have identified a possible problem. Did work on it and am just monitoring the system. If the problem still persist, I will sound out an SOS again. Thanks sprautzpng

07-02-2009, 05:42 AM	#9 (permalink)
bilbus TSF Enthusiast Join Date: Aug 2006 Posts: 950 OS: OS2 Warp	Re: Unwanted DNS Server What was the cause?