dns settings changes intemittently

[nikkie]

we are on a network with two DHCP servers with different IP range, all pc's
are listed under the reservation of the appropriate DHCP server with MAC
address mapping so we are sure on where the PC will get the IP address and
other settings.

i've been having problem on our network recently, i noticed that in the
middle of the session some client machines changes their DNS setting to the
DNS setting of the other DHCP server, although the IP, WINS etc. remains the
same....only the DNS changes, and once I do an ipconfig /renew it will
change to the correct DNS settings from our own DHCP server. what is the
possible reason why a client changes DNS in the middle of the session and is
there a way to solve this?

 

[nikkie]

i did ipconfig /all just now and found out that it changed again...i noticed
that it happens at specific time...like after PMand before 9AM...is thera ny
settings on the DNS where you setup the time to broadcast this settings?

 

[Ace Fekay [MVP]]

In

i did ipconfig /all just now and found out that it changed again...i
noticed that it happens at specific time...like after PMand before
9AM...is thera ny settings on the DNS where you setup the time to
broadcast this settings?

Did you create a Scope Option and Server Option as well with those
addresses? In your case, I would just create Scope Options, one for each
scope, and no Server options.

--
Regards,
Ace

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Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft Windows MVP - Windows Server - Directory Services

Security Is Like An Onion, It Has Layers
HAM AND EGGS: A day's work for a chicken;
A lifetime commitment for a pig.

 

[nikkie]

i just did what you've said and will observe if it will change. btw, what
is the difference between scope options and server options?

thanks

"Ace Fekay [MVP]"

 

[Kevin D. Goodknecht Sr. [MVP]]

In

i just did what you've said and will observe if it will
change. btw, what is the difference between scope
options and server options?

Server options are applied to all scopes, if you have one DHCP server
serving multiple scopes for multiple subnets you may want different options
on different subnets.

 

[nikkie]

thanks for this info, i already checked my settings and cleared up the
Server Options, I also asked the administrator of the other server to make
sure that server option is not set and he said that it's not all the while.
just now my dns settings changed again...is there any other thing to check?

 

[Ace Fekay [MVP]]

In

thanks for this info, i already checked my settings and cleared up the
Server Options, I also asked the administrator of the other server to
make sure that server option is not set and he said that it's not all
the while. just now my dns settings changed again...is there any
other thing to check?

The only time I've seen it "change" like what you're describing is if you
are using a DHCP Relay Agent on a non-MS machine. Do you have any IpHelpers
(Linux/Unix) or are you using a DHCP Relay agent on an MS machine or Cisco
router?

Ace