multihomed server on isolated networks

Alan DeKok aland at
Fri Mar 29 21:37:14 CET 2013

Lev Bronshtein wrote:
> On Fri, Mar 29, 2013 at 3:59 PM, Alan DeKok <aland at> wrote:
> What this means is that if my DHCP server has an interface in
> and another interface in, and it's server
> identifier is and that reply is sent out to the
> network the clients and routers on that network do not
> posses appropriate routing information to communicate with the DHCP
> server

  Ah, OK.

> I think this is exactly what I need.  Thanks so much!

  It should help.

  What you can also do is to leverage the configuration files.  They can
be used as a read-only key-value store, and queried at run time.  If
you've configured the DHCP server to listen on a particular IP, you'll have:

listen {
	type = dhcp
	ipaddr =


  You can then do:

	update reply {
		DHCP-DHCP-Server-Identifier := "%{listen:ipaddr}"

  Which sets the Server-Identifier to the "ipaddr" field in the "listen"

  It's a neat way to avoid more complicated configurations.

  Alan DeKok.

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