man dnsmasq
1) Можно запускать несколько копий:
-z, --bind-interfaces
is useful is when running another nameserver (or another instance of dnsmasq) on the same machine. Setting this option also enables multiple instances of dnsmasq which provide DHCP ser‐
vice to run in the same machine.
2)
--dhcp-range=
[tag:[,tag:],][set:,][,][,][,[,]][,]
--dhcp-option
=[tag:,[tag:,]][encap:,][vi-encap:,][vendor:[],][|option:|option6:|option6:],[[,]]
т.е. если отрабатывает
dhcp-range=interface:eth0,192.168.1.128,192.168.1.254,24h
то должна работать и конструкция
--dhcp-option = interface:eth0,option:router, 192.168.1.1
The optional set: sets an alphanumeric label which marks this network so that dhcp options may be specified on a per-network basis. When it is prefixed with 'tag:' instead, then
its meaning changes from setting a tag to matching it. Only one tag may be set, but more than one tag may be matched.