[Dnsmasq-discuss] Setting dnsmasq to serve multiple subnets

[john doe]

On 4/28/2022 6:20 PM, Will Dennis wrote:
> Hi all,
>
> I currently have dnsmasq set up and working well for the LAN that the dnsmasq server is on (for our purposes, say 192.168.0.0/24.) Config is like this currently:
>
> domain-needed
> bogus-priv
> strict-order
> no-hosts
> dhcp-authoritative
> dhcp-leasefile=/var/lib/misc/dnsmasq.leases
> domain=mycompany.com
> dhcp-range=192.168.0.20,192.168.0.59,1h
> dhcp-option=option:router,192.168.0.1
>
> Now, I have now set up a router (layer-3 switch) that has interfaces to multiple other networks off of it, all having a /28 network mask. It has been set to be a DHCP relay (“ip helper”) pointing DHCP requests from these new networks to the dnsmasq server. I cannot seem to find a “howto” on how to configure dnsmasq to serve multiple dhcp pools/associated options so it can be the single DHCP/DNS server for these multiple new networks. In my reading of the man pages, I *think* I’d have to do something like this in my config to enable this:
>
> domain-needed
> bogus-priv
> strict-order
> no-hosts
> dhcp-authoritative
> dhcp-leasefile=/var/lib/misc/dnsmasq.leases
> domain=nec-labs.com
> dhcp-range=192.168.0.20,192.168.0.59,1h
> dhcp-option=option:router,192.168.0.1
> dhcp-range=set:vlan10,192.168.1.1,192.168.1.13,255.255.255.240,1h
> dhcp-option=tag:vlan10,option:router,192.168.1.14
> […]
>
> Am I correct in this? And, I don’t need to tag the original pool/options, do I?

A fiew things:
- Do you realy need the router lines (the default in Dnsmasq are
reasonables)?
- The tags has nothing to do with VLAN tagging, they are internal to
Dnsmasq.

To answer your questions:
- Yes you are correct
- Given the sample above I would say no.

HTH.

--
John Doe