Gateway Router assigning same IP to two different machines!?? :(

[TechBoyJK]

Hello,

Here is what I got:

Cable modem

V

Router

V

Router Port 1

V

5port switch

V

4 Win 98se machines

Then from Router Port 2

V

WinME machine


The gateway router is assigning the same IP address 192.168.2.39 to two different machines. The other machines all end up with different IP addresses. So.... If one of the machines with the same IP is on the network, the others can surf the web no problem (not including the other sharing the IP address). It goes both ways, either one with the same IP can be on the network with the other machines and there is no conflict, but if both are on the network (turned on) the internet connection for both machines will crash, telling me I have an error with the MAC address of the machines.

I have gathered info via "WINIPCFG"

What might be causing this, and how do I change a machines IP manually? DHCP on the router is assigning the IP's and I cant think why it would assign the same IP to two different mac addresses.

ps. what is the equivalent to WINIPCFG for win2k?

 

[ScottMac]

The only way this could be happening is if you maybe edited your MAC address on the machines (and made two of them the same). DHCP issues the addresses based on the MAC address.

Try doing a /release and /renew on both and see if that resolves it.

Theoretically, you could have two NICs with the same MAC (I've seen it happen), but it's not s'posed to happen, every MAC address burned into a network interface is s'posed to be unique.

Good Luck

Scott

 

[bigshooter]

ipconfig from teh command prompt is kindof like winipcfg for win98. its jsut cli interface instead of a gui. ipconfig /all will give you all the info on the network configuration of the machine. ipconfig /release releases your dhcp given address and ipconfig /renew will get a new one. make sure all the machines are online when you get an IP, especially with win9x/me. it doesn't always look for a new ip when you start them up so if it has one it will keep it. if the machine was off and you requested an ip from another machien you may get the one the first machine had since the router no longer sees it. I don't know how long the dhcp leases lasts on your nat device so i can't give you a "for sure" answer. Put win2k/xp on all the machiens and you should not have any problems, unless like the first poster mentioned, you really do have the same MAC on two different computers.

 

[Bleep]

Looking over your configuration you have several machines on one port. I take it you are using ICS on these machines. If this is the case you have 2 DHCP servers, one on the router and one in the ICS machines. If this is the case that is where your problem is..

Bleep

 

[TechBoyJK]

I solved the problem. It wasn't the dual DHCP server issue, I had that before and learned. I solved the problem by running winipcfg on one of the machines, went to advanced options and released one of the conflicting machines from its dhcp lease. While it was released and unnassigned, I started the other machine, let it get the original conflicting IP, and then renewed the lease on the other machine. This gave it a new, acceptable IP and I haven't had a problem since.

Thanks for the help!

 

[bigshooter]

Yeah win9x sucks when it comes to dhcp. always have to release it, or you can just reserve an IP for each mac address. This will solve your problems if it happens again.