dhcpd sending on the same IP it receives on

[Jeffrey Hutzelman]

--On Tuesday, February 05, 2008 11:16:13 AM -0800 Jared Gillis 
<jared at sonic.net> wrote:

> Scott Baker wrote:
>> That seems like a semi-complex setup for just one server. Wouldn't it be
>> easier to just run two different (physical) servers for that odd corner
>> case you're running in to?
>>
>
> Sure, but this configuration is replicated for nearly 30 routers. 15
> servers serving 30 routers is far better for datacenter space, power,
> cooling and just financially than running 30 servers.

Even better would be to serve all 30 routers from one server (well, two or 
three, for redundancy).  Unless there is something weird about your network 
topology, there is no reason the DHCP server needs to be directly connected 
to the router.

Failing that, you could also configure the DHCP server's routing table such 
that traffic to each subnet goes to the appropriate router, such that the 
kernel will select the appropriate source address.


It would be nice if the DHCP server were to respond to unicast requests 
using the address to which the request was sent, but if I recall correctly 
that's not quite as trivial a code change as one might hope.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+ at cmu.edu>
   Carnegie Mellon University - Pittsburgh, PA