[Dnsmasq-discuss] IP address based on switch port number (option 82)

[richardvoigt at gmail.com]

On Mon, Feb 15, 2010 at 3:57 AM, Simon Kelley <simon at thekelleys.org.uk> wrote:
> I had completely forgotten about the server-address-override option.
> Thanks to Richard and Michael for reminding me about that. It is indeed
> supported and should solve the unicast renewal problem.

Sounds like an option (--relay-masquerade ?) is needed to enable this
behavior even when the relay didn't request it.  Or would that break
something?

>
> Ignacio, why not configure you switch to relay all ports? Then you can
> block broadcasts without problems. You don't have to have special
> configuration in dnsmasq for all the ports, it will do boring dynamic
> address allocation fine on relayed requests. (Remember that the netmask
> is not option in dhcp-range lines used by clients behind a relay.)
>
> Michael: the change I was thinking of should be completely transparent
> in all other situations except this. It just inhibits filtering of
> available dhcp-ranges by tag on a unicast DHCP renewal. Since by that
> time a lease will exist and the address is known, at most one dhcp-range
> can match anyway.

I don't think this is a solution.  If you moved a station between
ports, it would renew the address assigned to the old port, which both
doesn't meet the OP's stated requirement and leaves the next device
connected to the old port with no available address.

>
> Simon.,
>
>
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