DHCP hosed due to faulty NIC

camknows · 12-19-2007, 09:32 AM

Our ability to get DHCP addresses has been completely halted. There were a bunch of bad addresses in the DHCP scope, and after deleting them, I still have many coming back although not as many. However, the scope is now showing 51% free, it's been a while since I deleted those bad ones.

All these bad addresses are pointing to the very same MAC address. We believe this is a faulty NIC, which is still holding lots of addresses by itself.

A MAC search results in finding the vendor: Snell & Wilcox Ltd. No one is familiar with it. How else can we trace out this NIC? Thanks.

johnwill · 12-19-2007, 01:00 PM

Well, an adapter doesn't "hold" DHCP leases, however depending on how the DHCP server is coded, it can tie up a bunch of them until the lease runs out. Your mission seems to be to find the NIC in question and kill it.

camknows · 12-19-2007, 01:37 PM

After much searching, we narrowed it down to three NICs. All three systems were currently out of use, so we went ahead and unplugged. Seems to have cleared up the issue for the time being. Now, we have to figure out why it happened. Thanks.

johnwill · 12-19-2007, 04:29 PM

I've seen odd things happen when a NIC fails, all you need to do now is do an IPCONFIG /ALL on each system and see which NIC has the MAC address in question that is hosing the network.

12-19-2007, 09:32 AM	#1 (permalink)
camknows Registered User Join Date: Dec 2007 Posts: 3 OS: Windows Vista	DHCP hosed due to faulty NIC Our ability to get DHCP addresses has been completely halted. There were a bunch of bad addresses in the DHCP scope, and after deleting them, I still have many coming back although not as many. However, the scope is now showing 51% free, it's been a while since I deleted those bad ones. All these bad addresses are pointing to the very same MAC address. We believe this is a faulty NIC, which is still holding lots of addresses by itself. A MAC search results in finding the vendor: Snell & Wilcox Ltd. No one is familiar with it. How else can we trace out this NIC? Thanks.

12-19-2007, 01:00 PM	#2 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 31,468 OS: XP-Pro, Vista, Linux Blog Entries: 1	Re: DHCP hosed due to faulty NIC Well, an adapter doesn't "hold" DHCP leases, however depending on how the DHCP server is coded, it can tie up a bunch of them until the lease runs out. Your mission seems to be to find the NIC in question and kill it. __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience

12-19-2007, 01:37 PM	#3 (permalink)
camknows Registered User Join Date: Dec 2007 Posts: 3 OS: Windows Vista	Re: DHCP hosed due to faulty NIC After much searching, we narrowed it down to three NICs. All three systems were currently out of use, so we went ahead and unplugged. Seems to have cleared up the issue for the time being. Now, we have to figure out why it happened. Thanks.

12-19-2007, 04:29 PM	#4 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 31,468 OS: XP-Pro, Vista, Linux Blog Entries: 1	Re: DHCP hosed due to faulty NIC I've seen odd things happen when a NIC fails, all you need to do now is do an IPCONFIG /ALL on each system and see which NIC has the MAC address in question that is hosing the network. __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience