LTE5388-M804 loses network after some time

sysjohn

Today after 24h of working correctly, Ip changed and "kern.debug udhcpc: Sending discover..." messages started again, with no connection.

JeanFrancois

https://community.zyxel.com/en/discussion/comment/50625#Comment_50625

Again, this is certainly an issue but a different one 😀 The issue we are discussing here is a problem to handle correctly the IPv4 address changing, and not the ISP refusing to send a new IPv4 address.

Anyway @RobTheNetworkGuy do you have IPv6 enabled? If not, I suggest you force IPv4+IPv6 in APN and enable IPv6 in Cellular WAN (in Network Setting > Broadband sub-menu). In my case it reduces the frequency of the issue, as if IPv6 lease handling was a workaround for the IPv4 lease issue. However, after a few days I usually lose network again and have to reboot (APN change doesn't fix). But it's still better than an issue every 12 hours 🤣

JeanFrancois

I've been playing around with ZySH recently, and for what I've seen:

It's possible to restart the LTE connection in either changing the whole status of the APN, or only the anto/manual parameter of the APN. As far as I'm concerned, switching manual to auto and revert to manual usually do the trick 99% of the time so it's probably better to modify only this small parameter instead of disabling the whole configuration, my 2 cents.

Full APN disable/enable:

• cfg cellwan_mapn edit --Index 1 --AP_Enable 0
• cfg cellwan_mapn edit --Index 1 --AP_Enable 1

Small parameter change that do the trick:

• cfg cellwan_mapn edit --Index 1 --AP_ManualAPN 0
• cfg cellwan_mapn edit --Index 1 --AP_ManualAPN 1

Moreover, it seems that the incomplete command below is suffisant to restart (reload?) the connection:

• cfg cellwan_mapn edit --Index 1

Concerning a reboot command, I've seen 2 candidates:

• sys atcr [reboot] Reset to default, erase Data partition.
• sys resetcm Do reset CM.

Unfortunatly, I really cannot afford loosing Internet this week and the comments provided in CLI (in bold above) really don't help to figure out if it will kindly reboot or will revert to factory settings 🤔. As anyone any clue about those 2 different commands?

RobTheNetworkGuy

My Zyxel modem has been in this state since this morning. Neither of those reconfiguration commands seems to do the trick for me.

For turning the APN back to manual you also have to specify --AP_APN <apn>

I'm afraid to try the reboot commands at this time as I don't want to reset the whole configuration.

I noticed on the System Info page, it just says: WAN Information (No WAN)

In Zysh if I do cfg cellwan_mapn get, entry #1 is enabled with automatic APN.

cfg cellwan_status get reports that Status is "Down"

After a reboot via the web interface everything is working again, Status is back to Up and the System Info page WAN details are populated.

Btw I do seem to have ipv6 working. This failures occurs about once per week for me.

JeanFrancois

@RobTheNetworkGuy That makes sense. (1) When IPv6 is disabled, network is lost everytime DHCP changes the IPv4 address, every 12 hours in my case. APN "refresh" is sufficient to restore the conection. (2) When IPv6 is enabled, it seems to work a little better as if the IPv6 stack was detecting the change and update the config of the router including its new IPv4 parameters. However, after a few days (from 1 to 5 days or more), the connection gets lost again and this time APN "refresh" is not enough and a full reboot is required.

I will check cellwan_status next time.

RobTheNetworkGuy

Fwiw, I made this, and it works to remotely reboot the device from a cron job. It uses the web interface via a headless browser, so it's a bit of a heavyweight and fragile way to do it. But it works for me for now: https://github.com/RobFisher/zyxel_rebooter

JeanFrancois

https://community.zyxel.com/en/discussion/comment/50802#Comment_50802

Thank you for sharing this. I've been working on a way to "crontab" from pfSense using ZySH. Unfortunaly neither sshpass and expect are available in pfSense standard packages.

tonygibbs16

https://community.zyxel.com/en/discussion/comment/50838#Comment_50838

Hi @JeanFrancois

According to "TechBytes with Ron Nutter", Cron is already in pfSense at the command line, but there is a way to install a GUI for it, see

https://www.youtube.com/watch?v=1oNPwts0eFo

This Netgate forum post from 2008 suggests that pfSense does have Cron at the command line, see https://forum.netgate.com/topic/10646/cron-job-on-pfsense-how-to-create-one

I hope that this is helpful.

Kind regards,

Tony

JeanFrancois

https://community.zyxel.com/en/discussion/comment/50838#Comment_50838

@BruCom @RobTheNetworkGuy @Rabarbaro A few news:

• sys resetcm is interesting as it restarts the LTE module, you might try it next time you face the issue
• cfg cellwan_mapn edit --Index 1 is the fastest way to refresh the LTE connection, it's interesting if it's getting slow for example but won't fix the connection issue
• After my tests, I faced a situation were ifconfig was not showing wwan0 interface anymore and cfg cellwan_status get was telling LTE status Up… neither resetcm and cellwan_mapn were able to restore the missing interface and I has to reboot from the GUI

And now the most interesting part 😀

• sys atcr reboot will revert to default "saved" settings, and those settings are saved in "rom-d" whatever it is: by default these are factory settings
• zycli save_default save will save your current configuration into "rom-d", and at this time you can now use sys atcr reboot to reboot the device without loosing the settings!
• To revert the "rom-d" to default settings if you need to, 1st use zycli save_default clean and the sys atcr reboot

A full expect script is on progress, I need some more tests to finalize it.

JeanFrancois

Here comes the watchdog, please keep in mind:

1. ⚠️ Save your configuration with zycli save_default save otherwise it will reset to default settings!
2. Rename the file zyxel.exp and modify the IP address (and port if needed) and password of your device
3. Run with expect zyxel.exp password, or only expect zyxel.exp if you set your password in the script

zyxel.txt

@YeK @Zyxel_Support @Zyxel_AL Guys, it shouldn't be difficult to implement something like this internally 😇

PS: you might adapt thresholds depending on whether you have enabled IPv6 or not, because there is much less data received in pure IPv4 with a non-routable address