Re: Classic DHCP over bridge problem

From: Todd Knarr (tknarr_at_silverglass.org)
Date: 04/16/05 

Date: Sat, 16 Apr 2005 05:17:30 GMT

In comp.os.linux.networking <d3pm2t$sc4$1@ulysses.news.tiscali.de> Horst Knobloch <horschti2@gmx.de> wrote:
> Even if a bridge would do this (which it doesn't), it
> shouldn't confuse the DHCP server. The DHCP server
> looks into the DHCP request for processing and doesn't
> bother with the ethernet frame overhead.

How then would the DHCP server match on hardware address when the
DHCP request doesn't contain a filled-in hardware address field?
I know it can, so it's got to be looking at the Ethernet MAC
address on the incoming datagram.

> This should be the normal behavior but may be the
> XP bridging software behaves otherwise and processes
> the DHCP traffic in a more "creative" way.

A real hardware Ethernet bridge would retain the MAC address,
yes. This, however, is Windows doing the bridging. I'm not even
completely sure it's capable of transmitting with an arbitrary
MAC address as would be needed to be a real bridge. 

-- 
death.net: because for some problems there's only one solution.

Relevant Pages

  • Re: Network Communication Failure
    ... >>I disabled the bridge with no positive results. ... >>I've noticed when I do properties on the network bridge, ... >>I noticed that the Local Area connection and the 1394 ... A DHCP server automatically assigns an IP ...
    (microsoft.public.windowsxp.network_web)
  • Re: Linksys WAP11 as bridge - 1 connection
    ... Have a network with a WAP54G for the wireless... ... Have a WET11 bridge down in the family room for xbox + tivo... ... I have the WAP54G, an old desktop, print server, router, etc ... i seem to recal a similar prob when i had both my wrt's set to dhcp server on, and then there were two starting ip addresses.... ...
    (alt.internet.wireless)
  • Using Network Bridge, cant find DHCP Server
    ... I want to bridge my HPNA NIC to a Wireless NIC with Win2003. ... The Wireless NIC gets an IP from the DHCP Server at 192.168.123.254. ... I thought Network Bridge would be the answer. ... even with the same configuration settings as the Wireless NIC used to ...
    (microsoft.public.windows.server.networking)
  • Re: tap devices and DHCP.
    ... The other end runs linux as DHCP server on LAN. ... > It communicates with the DHCP server through the fxp0 device which is a ... > member of the same bridge. ... I see that tap1 does support broadcast but since it is a member of the ...
    (freebsd-net)
  • Re: Classic DHCP over bridge problem
    ... >> shouldn't confuse the DHCP server. ... > DHCP request doesn't contain a filled-in hardware address field? ... so it's got to be looking at the Ethernet MAC ... > A real hardware Ethernet bridge would retain the MAC address, ...
    (comp.os.linux.networking)