In investigating why megatron wouldn't talk to the network, I re-discovered the fact that it had been placed on its own private network to avoid conflicts with the 40m's test point manager. So I moved the linksys router (model WRT310N V2) down to 1Y9, plugged megatron into a normal network port, and connected its internet port to the rest of the gigabit network.
Unfortunately, megatron still didn't see the rest of the network, and vice-versa. I brought out my laptop and started looking at the settings. It had been configured with the DMZ zone on for 192.168.1.2, which was Megatron's IP, so communications should flow through the router. Turns out it needs the dhcp server on the gateway router (188.8.131.52) to be on for everyone to talk to each other. However, this may not be the best practice. It'd probably be better to set the router IP to be fixed, and turn off the dhcp server on the gateway. I'll look into doing this tomorrow.
Also during this I found the DNS server running on linux1 had its IP to name and name to IP files in disagreement on what the IP of megatron should be. The IP to name claimed 184.108.40.206 while the name to IP claimed 220.127.116.11. I set it so both said 18.104.22.168. (These are in /var/named/chroot/var/ directory on linux1, the files are 113.215.131.in-addr.arpa.zone and martian.zone - I modified the 113.215.131.in-addr.arpa.zone file). This is the dhcp served IP address from the gateway, and in principle could change or be given to another machine while the dhcp server is on.