Hi,
We are having an issue with DHCP when our ISP vendor tried to upgrade our Internet router.
The configuration and IP address of the new Internet router is same as the old one. Once they switched to the new one. The existing user can access to internal and external network without any issue. But if any of the staff tried to disconnect from network and re-connect. It will receive IP address conflict error and doesn't allow them to obtain an IP. Doesn't matter if it used static IP or DHCP.
When checking the Windows 2003 DHCP server, It had event ID 1020: Scope, 192.168.0.0, is 100 percent full with only 0 IP addresses remaining..
When checked the DHCP log from c:\windows\systerm32\dhcp. It showed below
11,04/08/16,19:58:06,Renew,192.168.0.104,L7P-aaa,F01FAF0F****,13,04/08/16,19:58:06,Conflict,192.168.0.104,BAD_ADDRESS,,
10,04/08/16,19:58:16,Assign,192.168.0.102,L7P-aaa,F01FAF0F****,
13,04/08/16,19:58:16,Conflict,192.168.0.102,BAD_ADDRESS,,
10,04/08/16,19:58:26,Assign,192.168.0.105,L7P-aaa,F01FAF0F****,
13,04/08/16,19:58:27,Conflict,192.168.0.105,BAD_ADDRESS,,
10,04/08/16,19:58:37,Assign,192.168.0.107,L7P-aaa,F01FAF0F****,
13,04/08/16,19:58:37,Conflict,192.168.0.107,BAD_ADDRESS,,
10,04/08/16,19:58:47,Assign,192.168.0.108,L7P-aaa,F01FAF0F****,
13,04/08/16,19:58:47,Conflict,192.168.0.108,BAD_ADDRESS,,
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10,04/08/16,20:06:55,Assign,192.168.0.150,L7P-abc.office.internal,F01FAF0F****,
13,04/08/16,20:06:55,Conflict,192.168.0.150,BAD_ADDRESS,,
14,04/08/16,20:07:05,Scope Full,192.168.0.0,,,
It looks like one machine tried to obtain an IP from DHCP, then received conflict error and DHCP server marked the IP as BAD_ADDRESS. It then tried to obtain another with the same error. Then all the way up to the end of DHCP scope range.
When I tried to restart the server. It marked all the BAD_address expired and deleted. But when another PC tried to connect. it filled out with same above event and filled out the DHCP scope again.
The interesting thing is, the DHCP scope is only from 192.168.0.100 to 192.168.0.150. When I asked the guy to manually setup a static IP as 192.168.0.11, which is out of DHCP range and it was not in used (didn't respond from ping). He got the same error.
He also tried to run ipconfig /release and ipconfig /renew and it didn't make any difference.
We then rolled it back to the old router and the issue disappeared. The vendor couldn't figure what was the cause, as they confirmed that the new router was configured exactly the same as the previous one
There is only one DHCP server locally in the subnetwork. The server is also DNS server and domain controller.
The client PC is mix with laptop/desktop with different OS of Win7/Win8
Can anyone please provide any suggestions on this issue?
Thanks in advanced,
Wei