[Dnsmasq-discuss] Dnsmasq, multiple subnets/gateways and option 82

[Keith Lyons]

Hello,

I recently built a DHCP server using Dnsmasq on Centos7 VM and had a
question about having more than one subnet and gateway

We are using Option82 for 15 devices on each subnet, at this time only one
subnet is active but I expect that the other two subnets will need to be
active in the very near future.

Currently I have dhcp-option=3,10.192.4.1 set for the active subnet, I
will need to add 10.192.5.1 and 10.192.6.1 for the others as they come
online. I have seen some other posts about utilizing multiple nics, each
assigned to one of the subnet, is this the best
way to accomplish what I am attempting to do?

There will be nothing else requesting DHCP from the server, only the 15
devices - the other two subnets will be similar to this.

Thanks,

Keith

[Chris Novakovic]

Post by Keith Lyons
Currently I have dhcp-option=3,10.192.4.1 set for the active subnet, I
will need to add 10.192.5.1 and 10.192.6.1 for the others as they come
online. I have seen some other posts about utilizing multiple nics, each
assigned to one of the subnet, is this the best
way to accomplish what I am attempting to do?

It's certainly the easiest. You'll find that the interface name can also
be used as a tag, allowing for the following setup:

interface=eth0,eth1,eth2
dhcp-range=tag:eth0,10.192.4.2,10.192.4.254,10m
dhcp-range=tag:eth1,10.192.5.2,10.192.5.254,10m
dhcp-range=tag:eth2,10.192.6.2,10.192.6.254,10m