I am using a Private APN with AT&T on a set of RV55s running ALEOS 4.14 and AT&T modem firmware (EM7511 1.14.02.00). When the private addresses are assigned by AT&T to all the modems their auto defined gateway is at IP XXX.XXX.0.1 (one of the RV55 modems in the Private APN).
The issue is all the other devices (not assigned the XXX.XXX.0.1 address appear as though they can reach XXX.XXX.0.1 but the response times do not line up. They are sub millisecond confirming the traffic is not flowing OTA to the cell towers to the RV55 device assigned XXX.XXX.0.1 .
Another issue is the RV55 that has the XXX.XXX.0.1 IP assigned cannot reach any of the other RV55s on the Private APN. However all other RV55 devices can talk to each other over the Private APN (100ms+ response times).
I have worked with AT&T and had the XXX.XXX.0.1 address reassigned as XXX.XXX.0.11 and now that device can talk to all other devices on the Private APN. They had no explanation for this behavior since all assignments are the same in their addressing database. They asked I contact Sierra Wireless to review the issue and see if it is a firmware problem or something else.
I feel this issue wasn’t present in a previous AT&T modem firmware but I don’t know how to fetch the version (1.07) or if a downgrade is possible. Maybe there is another explanation for this behavior so appreciate any feedback.