IP address conflict

[Wy]

My home network consists of a laptop (wireless), 2 desktops (on board nics),
1 desktop (PCI wireless adapter) a print server and a wireless Linksys
router (WRT54G). All the computers are running WinXP Pro. I have DHCP
enabled on the router to send out only 10 ip addresses (range from
192.168.1.15 - 192.168.1.25). The print server is the only one that's
assigned a static ip address. At least once a week I'm getting an error
that says there is an IP address conflict with another system on the
network. Is there a way to prevent this from happening?

I'm probably leaving out some needed info so please feel free to ask for
more details.

Thanks in advance,
Wy

 

[Lem]

My home network consists of a laptop (wireless), 2 desktops (on board nics),
1 desktop (PCI wireless adapter) a print server and a wireless Linksys
router (WRT54G). All the computers are running WinXP Pro. I have DHCP
enabled on the router to send out only 10 ip addresses (range from
192.168.1.15 - 192.168.1.25). The print server is the only one that's
assigned a static ip address. At least once a week I'm getting an error
that says there is an IP address conflict with another system on the
network. Is there a way to prevent this from happening?

I'm probably leaving out some needed info so please feel free to ask for
more details.

Thanks in advance,
Wy

Just to confirm, the static IP assigned to the print server is outside
the range 192.168.1.15 - 192.168.1.25? And you do have WPA or WPA2
encryption enabled?

Is there any consistency to what you are doing when you get the error
message?

At a time when the error occurs, access the router and check the DHCP
clients table (Status > Local Network > DHCP Clients Table). This will
give you the MAC addresses of the devices to which IP addresses have
been allocated. You can find the MAC address of each computer by
running ipconfig /all on each.

 

[Wy]

Thanks Lem for your reply. The print server is within that range. Should
it be outside that range? I'm using WPA2 encryption.

I'm not doing anything when it happened. I woke up yesterday morning and
opened the laptop and thats when I saw the error. I went in my office where
the router is and saw the same thing on one of the desktops. Neither of
them were in use when the error occured. So what I did was unplug the
adapter from the router for 30 secs to get another IP addy for the desktop.
I was pressed for time so I didn't bother with the laptop but when I got
home last night I had to do the same thing I did in the morning.

I'll have to do your last suggestion when it happens again. I tired to
release and renew both but that didn't even work.

Wy

 

[Malke]

Thanks Lem for your reply. The print server is within that range. Should
it be outside that range? I'm using WPA2 encryption.

I'm not doing anything when it happened. I woke up yesterday morning and
opened the laptop and thats when I saw the error. I went in my office where
the router is and saw the same thing on one of the desktops. Neither of
them were in use when the error occured. So what I did was unplug the
adapter from the router for 30 secs to get another IP addy for the desktop.
I was pressed for time so I didn't bother with the laptop but when I got
home last night I had to do the same thing I did in the morning.

The print server's static IP should be *outside* the range of addresses
assigned by the DHCP server (the router). This is why you are getting
the error. So if your router assigns IP addresses 192.168.1.10-50 for
ex., make the printer 192.168.1.200.


Malke

 

[Wy]

The print server's static IP should be *outside* the range of addresses
assigned by the DHCP server (the router). This is why you are getting the
error. So if your router assigns IP addresses 192.168.1.10-50 for ex.,
make the printer 192.168.1.200.


Malke

Ok i'll try that when I get home tonight. Thanks Malke. Another quick
question for future reference.
How can find out which systems are having the conflict?

Wy

 

[John Wunderlich]

Thanks Lem for your reply. The print server is within that range.
Should it be outside that range? I'm using WPA2 encryption.

You have assigned ownership of the range 192.168.1.15 - 192.168.1.25 to
DHCP. Static addresses are not managed by DHCP and therefore must
exist outside of the range owned by DHCP. This is most likely your
problem.

The question about the encryption was probably to rule out an external
eavesdropping device.

-- John

 

[Malke]

Ok i'll try that when I get home tonight. Thanks Malke. Another quick
question for future reference.
How can find out which systems are having the conflict?

Fix the printer first and that may take care of everything. If you have
static IPs assigned to any other devices, don't forget to fix them, too.


Malke

 

[Lem]

Ok i'll try that when I get home tonight. Thanks Malke. Another quick
question for future reference.
How can find out which systems are having the conflict?

Wy

As Malke and John said, you need to assign all static IP addresses
outside the range of addresses that may be assigned by the router's DHCP
server (and yes, I asked about encryption to rule out an intruder).

As for finding out which systems are having the conflict, that's why I
suggested looking at the router's DHCP clients table. That table lists,
by MAC address (which is unique to each piece of hardware), the IP
address that the router has currently assigned. If you go to each of
your computers in turn and run the command ipconfig /all in a command
window, you can create a list of the MAC addresses (the ipconfig display
calls them "physical address") corresponding to the different computers
(actually to the network interface cards in the computers). With that
list and the DHCP Clients Table, you can easily see what computer lost
out to the print server (or vice versa, if the print server isn't always
powered up).

 

[Jim]

Ok i'll try that when I get home tonight. Thanks Malke. Another quick
question for future reference.
How can find out which systems are having the conflict?

Wy

The duplicate ip address exists on the network. Hence, all of them should
report an error.
Jim