So before I ask this, please note that I solved the problem through fiddly hacking, but it still mystifies me.

I am a Unix nerd. I have a pretty complex setup of switches, Unix machines acting as firewalls, and run my own DHCP and DNS servers. I got my new Apex, and plugged it into the network, expecting it to just reach out to DHCP and grab an address. It did not, and this confused me alot.

Finally I got a laptop, a switch, and tcpdump, and isolated it down. What I found was this, if the Apex was plugged directly into the switch, and the laptop was plugged into the same switch, with nothing else attached to the switch, I saw no traffic from the Apex. No DHCP requests, nothing. But then, if I plugged the Apex directly into the ethernet on the laptop, I got DHCP requests immediately. (I was also somewhat surprised to not need a crossover cable for this)

Is the Apex doing something silly that causes it's DHCP requests to not propagate off a switch?

For those wondering how I solved this, I ended up just installing dhcpd on the laptop, setting up a super simple config, getting it an IP, and then logging in so I could hardcode a static IP for the device. It works fine on my network once I did that. ( My plan was always to be static anyhow, so whatever, it's just that it was a frustrating 3 hours trying to figure out why it wouldn't connect )