Especially if you cant ping past the switch like the FW.
That was my first thought, although warped by the fact that a FEW miners were continuing to work just fine. Swapping parts now to try and isolate. Its almost feeling like I have a double failure somewhere.
And now another anomaly: Even when I get the network to the point where I can ping the machine, somewhat under half of them keep rebooting themselves. (FYI: Its a nice cool day, no temperature problems). I've even disabled all Awesome Miner rules that would do that, but still seeing a few reboots. For instance, I'll see 66 of my 76 14TH machines finally make it up, only to have 30 of them reboot.
Update: Well, one GS316 was definitely flaky. Swapped my left side one for my right side one and the right side came up, and the miners are stable. Either I have (3) bad switches, all that died at 9am this morning (and yes, they are on UPS power), or something else going on.
Update 2: Progress, all but 21 devices are up.
Update 3: All but one L3 up and running. All (26) L3s appear to be normal, no red light, network lights flashing, green light flashing. Pretty near impossible to find after this stressful day. I can live with it until I get some sleep and booze.
The primary problem was a bad network switch between the firewall and the edge switches. I'm upgrading both of those "core switches" (If you can call them that, since they are unmanaged) to Netgear Pro series. Discovery was complicated by partial functionality on an intermittent basis. Discovery was also hampered by a backup switch (an old 8-port TP-Link I had left over) also not working reliably.