----- Original Message ----- From: "Crist J. Clark" <[EMAIL PROTECTED]> To: "taproot420" <[EMAIL PROTECTED]> Cc: "'James A. Robbins'" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Wednesday, August 14, 2002 1:19 AM Subject: Re: cant get dhcp to pass through bridge. ! please help
> On Mon, Aug 12, 2002 at 03:29:00PM -0500, taproot420 wrote: > > Already present on the bridge. > > > > # cat bridgename.bridge0 > > add sis0 add sis1 blocknonip sis0 blocknonip sis1 up > > > > I thought dhcp used ip to handshake. > > It does. It uses UDP riding on IP. Ports 68 and 69 to be > exact. Nothing about DHCP is specific to Ethernet either. It's IP all > the way. My bad, you right. I just double checked another firewall that we set up to pass DHCP and found that we had to include rules to pass packets with a destination address of 255.255.255.255 in both directions to allow DHCP to work. The requests are sent to the ultimate broadcast address to try to contact any DHCP server within hearing range. I assume that 255.255.255.255 is blocked by a router up the line somewhere so that the entire Internet doesn't get these requests. -- James A. Robbins Network Engineer The Ohio State University Chemistry Department
