Cannot get ip address from dhcp even reinstal tcipi

[12345671]

One toshiba laptop with winxp cannot get IP address from DHCP server, it can only use fixed ip address.

When ipconfig /renew, the error is : cannot contact dhcp server, dhcp request time out. Other PC can renew DHCP, so it means dhcp server works properly. Same problem when use network repair utility in winxp.

I have tried reinstall tcp/ip and installed a winsock fix from

http://members.shaw.ca/techcd/VB_Projects/WinsockFix.zip

Still doesn't work. Any advise is appreciated!!!!

 

[jouell]

What is your network config? Is this a local lan? wan?
Is the failing client behind a router? Any errors on the dhcp server? what os/version is the server?

 

[12345671]

This laptop is a normal client on uni LAN. The DHCP server on the LAN is windows. The problem is solved, but we don't know why.

First,the laptop could only use fixed public B IP address, couldnot get one IP address from DHCP server. Then I tried to reinstall tcp/ip and installed a winsock fix from

http://members.shaw.ca/techcd/VB_Projects/WinsockFix.zi...

, it still couldnot get IP address from DHCP server.

Then now it can get IP address from DHCP server. But we didn't change anything except reboot. No idea why it is solved.

Is the following a reason? This laptop often travels to another LAN which use 192.X.X.X as its private IP address pool. But both LAN use DHCP to assing IP addresss. Seems each time, this laptop comes back from LAN with private IP address to the uni LAN, it meets this problem.

Any advice for this reason?

 

[jbud]

A feature of windows DHCP clients is that it will hold the lease it receives from a server, even after unplugging or rebooting:

http://support.microsoft.com/default.aspx?scid=kb;en-us;167014&Product=win2000

Perhaps the lease survived the uninstalling/re-installing you did.

The best solution may be to ipconfig /release before unplugging from one subnet and ipconfig /renew when plugging into the new one.

 

[12345671]

I will try your solution next time.
This laptop's IP address could be one of the three:
(1) among 192.168.0.X subnet mask is 255.255.255.0, or
(2) among 135.116.18.X subnet mask is 255.255.255.0 or
(3) it has a dial-up connection by modem when people use it at home
For the first 2 posibilities, DHCP server should not think they are from same subnet according to the website you suggested?