Hi Hopkins35 and welcome to the forum!
Sounds like you have the same setup as mine: a Firebrick with several VMG1312-B10As connected to it. But as I have more than three modems, I don’t have sufficient free ports on the Brick and so I have to use VLANs assigned to the modems and a VLAN mux/demux switch as recommended by AA. But I’m assuming you don’t need to use VLAN MUXing ? That would be the one difference?
Could you give me a specific example (suitably obscured) ?
Sanity check: Why would the Brick be losing connectivity? Is it because it thinks it has a MAC address for an IP address associated with the modem already and therefore doesn’t ARP it when it in fact needs to?
The same is true for the modem: it could be a problem in the modem’s ARP table, as opposed to that of the Firebrick, but then it’s not visible to us.
Does the system then regain a state of goodness when the bad ARP entry ages out and the Brick or modem needs to look up the MAC address for an IP address instead.
Do you think it is the modem getting screwed up or a bug in the Firebrick?
Could you post something in the Firebrick users’
mailing list perhaps ?