IP Address Confilict

[North Coast Sea Foods]

On occasion I am getting an IP Address Conflict message.

What is the best way to identify where this is coming from?

thx

 

[SBS Rocker]

ping -a xxx.xx.xx.xxx

or check you DNS records.

"North Coast Sea Foods" <jleonard@northcoastseafoods.com> wrote in message
news:enDkzkxwHHA.4568@TK2MSFTNGP03.phx.gbl...
> On occasion I am getting an IP Address Conflict message.
>
> What is the best way to identify where this is coming from?
>
> thx
>
>

 

[TuxEdu]

On Jul 10, 12:40 pm, "North Coast Sea Foods"
<jleon...@northcoastseafoods.com> wrote:
> On occasion I am getting an IP Address Conflict message.
>
> What is the best way to identify where this is coming from?
>
> thx

Try using

nslookup XX.XX.XXX.XXX

 

[Todd H.]

"North Coast Sea Foods" <jleonard@northcoastseafoods.com> writes:
> On occasion I am getting an IP Address Conflict message.
>
> What is the best way to identify where this is coming from?

Event logs on the machine throwing the message might tell you the mac
address or name of the conflicting device. Or arp -a will dump the
arp table of your machine and tell you the MAC of the machine that
also has that IP. Then, from the MAC address you might be able to
divine the vendor of the network device and narrow things down from
there. Then it's a linear search, checking all your machines.. and
that's not terribly productive or fun.

But you're learning why a managed switch is a nice thing to have.

The best way to chase this down is on your network switch. On a
proper managed switch (hopefully you have one), dupe ip's should be
reported and you'll have port numbers you can go and follow to the
offending party. Dump the address table and it should tell you.

Absent a managed switch though, a manual method of doing this would be
to jack into your switch with a laptop using a good non conflicting IP
on the subnet, unplug every other cable except your line from the
switch, ping -t the offending address, replug wires until you get a
response. Repeat if your first hit was the server that reported the
duplicate to ya.

On a related note, if your environment is using DHCP, and if the dupe
IP address in the dhcp scope range? You can check the lease list and
see the MAC of what should have that address, then go about chasing
down what other machine is using that address. No one should be
assigning themselves static IP's within the DHCP scope.

Good luck.

Best Regards,
--
Todd H.
http://www.toddh.net/

 

[Brad Tiede]

Mystery Duplicate IP address

Ok... here's a related question then. I've got a 2003 server that claims it has a duplicate IP address, but never loses connection. I checked for the MAC of the culprit in the Event Log and it shows 00:00:00:00. I can ping the address with the server up, unplug the server and the pings time out.

Any ideas?

EggHeadCafe.com - .NET Developer Portal of Choice
http://www.eggheadcafe.com

 

[Greg O]

Re: Mystery Duplicate IP address

<Brad Tiede> wrote in message news:200772016313btd@hamilton.net...
> Ok... here's a related question then. I've got a 2003 server that claims
> it has a duplicate IP address, but never loses connection. I checked for
> the MAC of the culprit in the Event Log and it shows 00:00:00:00. I can
> ping the address with the server up, unplug the server and the pings time
> out.
>
> Any ideas?
>
> EggHeadCafe.com - .NET Developer Portal of Choice
> http://www.eggheadcafe.com

You could check DNS to see if the other computer has registered its name
with the IP address, that will tell you which computer is is perhaps.