One DHCP server, two VLANs?

[Karl Denninger]

On 1/12/2016 15:04, Simon Hobson wrote:
> Karl Denninger <karl at denninger.net> wrote:
>
>> This seems like it should be possible without a lot of hand-wringing, but I can't find the magic smoke recipe for it....  :-)
> It is simple - you're just over thinking it !
>
>> Topology is ...
>> The DHCP server is on both VLANs via virtual interfaces (FreeBSD) with the port on the switch being told to send both through; it sees and handles traffic from both VLANs just fine.
>>
>> But.... I cannot start two instances of dhcpd (one on each sub-interface.)  Nor can I find a way to tell dhcpd to read requests from both.
> You just start one instance, but in that instance you define both subnets. So say your subnets are 192.168.1.0/24 and 192.168.2.0/24, then you need a config file a bit like this :
>
> subnet 192.168.1.0 ...
>   router ...
>   ...
> }
> subnet 192.168.2.0 ...
>   router ...
>   ...
> }
>
> Then make sure that it listens on both interfaces. The default is to listen on all broadcast capable interfaces, but distribution specific startup scripts may read settings from a file and limit that.
>
> In operation, the daemon tracks the packets and the interface they arrive through - from this is knows which subnet any request is for, and the rest happens automagically.
>
> _______________________________________________
>

Well that's what I get for trying to get too cute :-)

Thanks.

-- 
Karl Denninger
karl at denninger.net <mailto:karl at denninger.net>
/The Market Ticker/
/[S/MIME encrypted email preferred]/
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