Strange DHCP problem

[jojo]

Hi, I have a problem in my office network.
When some PCs disconnect from network in some reason (eg unplug
network, restart NIC or ipconfig /renew), the PC will get a
10.254.254.X in 255.255.255.0 subnet mask with 10.254.254.1 default
gateway.
However, the DHCP should only distribute 192.168.9.X with 255.255.255.0
subnet mask.

I have to disable the NIC in widnows and unplug the network cable. Then
re-plug in the cable and re-enble the NIC. The PC will automatic get a
correct ip.

But when I browse the address lease in DHCP, I can't find the new ip i
got. Even I press the refresh button many times.

The other problem is, even I get the ip, but I will get a expire time.(
The DHCP server was set unlimited in lease time)

Anyone has any idea about my problem?

Thank you in advance.

Regards,
Chi

 

[Andrei Ungureanu [MVP]]

maybe somebody else have put another DHCP server on your network (or maybe
you have set "alternate configuration" on your PC - check that in the TCP/IP
properties)
When you get an IP from 10.254.254.X do an IPCONFIG /ALL and check what DHCP
server has offered that IP address.

--
Regards,
Andrei Ungureanu
www.eventid.net
Test our new EventReader!
http://www.altairtech.ca/eventreader/default2.asp?ref=au

 

[jojo]

Thanks for reply
Yes, someone was put a router to testing some equipment in our office.
Those 10.254.254.X ip were distributed from it.

However, I don't understand why.
When I get an ip (192.168.9.132) and I type ipconfig /all in cmd. It
shows the expired date is 2038-1-19 11:14:07am. However, when I check
in Address Leases in our DHCP server. It shows the expired date is 2
hour after I obtained that ip.

Since in our office, sometimes will happen ip collision. (no one was
set static ip). We suspected is dhcp problem.

Could anyone give me an idea how to solve it?

Thank you

Andrei Ungureanu [MVP] 寫é“：