Subject: Re: netboot question
To: None <>
From: Robert Elz <kre@munnari.OZ.AU>
List: current-users
Date: 11/13/2003 23:18:02
    Date:        Thu, 13 Nov 2003 16:29:32 +0100
    From:        <>
    Message-ID:  <>

  | can I use a gateway - which forwards BOOTP/DHCP requests
  | from one subnet to another - in order to boot a
  | client from network?

Yes, that's a dhcp relay (bootp relay, more or less the same thing).
That's an integral part of the dhcp protocol.

  | the documentation says: it's not a good choice... is that true?

There are some issues that can arise when booting through gateways,
but it usually works in most environments (of course, the protocol
you're using for actually fetching the boot image needs to be able
to cope, as well as bootp/dhcp which do little more than configure
your network).

  | the server is an i386 PC and the clients are Alpha 500-s as the gw too.

If the alpha that is the gatway is running NetBSD (or some BSD) then
to act as a dhcp relay it needs to run the dhcrelay utility.

That's a standard part of NetBSD (no packages required).   To run it
you just need to enable it in rc.conf

dhcrelay=YES  dhcrelay_flags='-i xxx0'

where 'xxx0' is the interface from which you want to forward packets,
and is the IP address of the DHCP server (which should be
reached out some other interface).   The -i xxx0 is optional (in which
case it will forward from all interfaces) - it can also be given
multiple times (see the dhcrelay man page).