DHCP strangeness... [Archive] - Glock Talk

PDA

View Full Version : DHCP strangeness...


aspartz
05-18-2005, 13:49
In the process of upgrading my firewall this weekend I noticed somethin strange.

When I connect my workstation directly to the cable modem, DHCP returns an IP of 204.x.x.x/24. (I got this from ipconfig)

When I connect my linux box (firewall) up to the cable modem, the returned IP is 63.x.x.x/22. (I get this from ifconfig).

This seems strange to me. Which is correct?

ARS

HerrGlock
05-18-2005, 15:03
They may be both correct.

Can you connect outside with either machine when it is connected? If so, they may have a DHCP server that answers WIN calls and another that answers other than WIN. Yes, there is a difference.

Have you waited a while and tried it again? It may be going off MAC address and giving the same IP range to the same MAC address.

DanH

aspartz
05-18-2005, 17:13
Originally posted by HerrGlock
They may be both correct.
...
Have you waited a while and tried it again? It may be going off MAC address and giving the same IP range to the same MAC address.

DanH
I talked to the ISP today. Both are correct. Apparently, even though I release the DHCP lease, that IP is still associated with a given MAC address for the original period of the lease. They just happen to have a disparate collection of IP's issued to them.

I didn't ask if they supported IPv6 yet ;f

ARS