I have the same hardware setup for about a year now. My service is Visible wireless. Once in a while I have the same issue as described in this discussion. Since my connection works 99% of the time I have attributed it to the network....although I could never seem to be certain. Just had it happen in the same time frame of this discussion thread. One observation from me.....
I tried a hard reset on both the M2 board and AXT1800 with a router rebooter I built out of a sonoff S31 plug. The device pings a user defined ip on a constant basis....when it loses connection for a preset time frame it essentially powers down the whole setup for 10 seconds and restarts. This doesn't always work to solve the problem. What does work almost always is an abort and reconnect in the cellular section of the internet screen. I'm still puzzled about this issue.
Wondering if there are any updates or fixes to the problem outlined by @will12345. I only had the “the interface is connected but the intended cannot be accessed” problem sporadically but now the RM520 modem is practically unusable…..problem happens every five minutes or so. I downgraded to the 4.4.6 firmware but it didn’t solve the problem. It’s ridiculous to have to keep rebooting the router.
I had to switch back over to using a cell phone tethered for the time being. I'm traveling right now so it may take a few days but will try to send you a log output when I get a chance.
Ok. I'm back trying to trouble shoot the problem. As I mentioned, I can't stay connected to the internet with the M2 dev board modem. I get the error “the interface is connected but the intended cannot be accessed” after about 3 to 5 minutes every time I re-establish the connection. It is very frustrating to say the least. You asked for the log file.....do you want the last events in the system log when the error appears? I can copy and paste that if it helps. Let me know how to proceed.
Another update. I reverted back to 4.4.6 firmware with the keep settings button enabled so I wouldn't have to re-configure all my wifi setting and a couple of static ip's I had reserved. After the firmware downgrade the problem of losing the internet connection persisted. It was also happening with my iphone 8 tethered to the ATX1800 so it told me it wasn't the GL-M2 modem only. My next course of action was to do a clean install of firmware 4.4.6 and reconfigure all my preferences. After performing this, all the problems so far have disappeared.....the M2 board works fine and so does tethering with an iphone. Based on these findings I am certain that something changed in the firmware past the 4.4.6 firmware release and it is the root of the problems. Now need to figure out what it is.
Well....I may have spoke a little too soon. I did have a disconnect overnight last night. The unfortunate reality is that when it happens it doesn't try to reconnect on it's own.
Maybe there is a script or a plugin you can provide that will reset the modem when it loses a connection? Once the connection is lost it just sits there until I hit the disconnect reconnect button. Rebooting the router seems like overkill for this issue.
May have come up with the solution to my problem. Have had router and wireless connection running stable on the latest firmware rel. 4.6.8. I don't get this error message any longer “the interface is connected but the intended cannot be accessed”. I was having to re-boot the router to re-establish connection when this occurred.
Solution: I followed some instructions from another forum to change the IMEI of my quectel modem to that of my android cell phone that I originally used when I activated my Visible account.
I performed the following at commands.
AT+EMGR=1,7,"enter your IMEI here"
AT+QPRTPARA=1 (make a note of modem original IMEI in case you need to restore it.)