Multiple source ports about massdns HOT 1 CLOSED

Due to massdns using a single socket, it is not currently possible to randomize the source ports without the use of additional tools.
Using the packetrand tool from the freebind project, which now supports source port randomization, you should be able to achieve what you want though. You would bind MassDNS to a fixed port in this case and instruct iptables to pass all packets to and from the DNS resolvers to the netfilter queue which packetrand is attached to and specify the MassDNS port using packetrand's -r argument.

from massdns.