DNS allowing same ip for multiple clients

G

Guest

the DNS server (windows server 2003) appears to be allocating the same ip
address for multiple computers.

obviously this is causing connectivity problems across the LAN.

for example when using VNC when i type in the name of the client pc (eg
comp1) i connect to comp3. Very strange......

how do i prevent the dns from giving the same ip address to more that one
pc? I didn't think this was possible.
 
J

Jeff Cochran

the DNS server (windows server 2003) appears to be allocating the same ip
address for multiple computers.

DNS doesn't allocate IP's.
obviously this is causing connectivity problems across the LAN.

No it isn't. Having the same IP on two systems will cause problems,
but DNS just registers the IP, it has nopthing to do with how the
system gets the IP address.
for example when using VNC when i type in the name of the client pc (eg
comp1) i connect to comp3. Very strange......

Not really. If DNS points "comp1" to the IP address currently used by
comp3, this is normal.
how do i prevent the dns from giving the same ip address to more that one
pc? I didn't think this was possible.

You can't. DNS doesn't assign IP's. DHCP does, or can. Configure
your systems and your DHCP correctly.

Now, do you really have systems with the same IP or do you have an
issue with DNS records showing two names pointing to the same IP? If
the latter, delete the incorrect record.

Jeff
 
G

Guest

ok i ping both ip addresses that appear to be assigned to the one pc. both
resolve to the same FQD.

is this not DNS?
 
G

Guest

thanks for the response.

checked DHCP there are two seperate ip addresses. nothing appears unusall.

removed both dns entries and ipconfig /flushdns and /registerdns on both the
effected pcs.

they still appear to have the same ip address an the original problem.
 
J

Jeff Cochran

thanks for the response.

checked DHCP there are two seperate ip addresses. nothing appears unusall.

removed both dns entries and ipconfig /flushdns and /registerdns on both the
effected pcs.

they still appear to have the same ip address an the original problem.

Did you check the client TCP/IP settings?

Jeff
 
J

Jeff Cochran

ok i ping both ip addresses that appear to be assigned to the one pc. both
resolve to the same FQD.

Okay, two IP address under one name or two names pointing to the same
IP address?
is this not DNS?

That's DNS. But you said your PC's were getting allocated the same IP
address. That's not DNS.

Check the client PC for TCP/IP settings. If it's static, check both
to make sure you have two separate IP addresses. Actually, check if
it's dynamic as well. At a command prompt on the client do a IPCONFIG
/ALL and look at the IP addresses and see how they are assigned (is
there a DHCP server).

If the IP's are different, remove both IP addresses in your DNS
server. If you use dynamic IP registration in your DNS, do not add
them again. If you do not, manually add an A record for each system
name with the correct IP. Turn *everything* off and back on again.
Check the IP's on the clients. Ping the IP address. Then ping by
name.

Jeff
 
A

Ace Fekay [MVP]

Jeff said:
Okay, two IP address under one name or two names pointing to the same
IP address?


That's DNS. But you said your PC's were getting allocated the same IP
address. That's not DNS.

Check the client PC for TCP/IP settings. If it's static, check both
to make sure you have two separate IP addresses. Actually, check if
it's dynamic as well. At a command prompt on the client do a IPCONFIG
/ALL and look at the IP addresses and see how they are assigned (is
there a DHCP server).

If the IP's are different, remove both IP addresses in your DNS
server. If you use dynamic IP registration in your DNS, do not add
them again. If you do not, manually add an A record for each system
name with the correct IP. Turn *everything* off and back on again.
Check the IP's on the clients. Ping the IP address. Then ping by
name.

Jeff

I just want to add we may need to check WINS here too, if he's using WINS.


--
Regards,
Ace

Please direct all replies ONLY to the Microsoft public newsgroups
so all can benefit.

This posting is provided "AS-IS" with no warranties or guarantees
and confers no rights.

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

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