GL-AXT1800 + GL-M2 (RM520N-GL): Lose internet access

Will12345 · May 13, 2024, 1:18pm

I have a GL-M2 with RM520N-GL connected to the GL-AXT1800 router. After a few hours or days, the router would report error:

The interface is connected, but the Internet can't be accessed.

The internet can be accessed again if the router is rebooted. The USB modem DOES NOT need to be rebooted. This makes me think there is an issue with the router and not the USB modem.

This issue occurs on all of the firmwares I have tested on AXT1800:

4.2.3
4.4.6
4.5.16

Does anyone have similar issues?

My GL-X3000-5G on firmware 4.4.8 DOES NOT have this issue. The GL-X3000-5G stays online for days/weeks using the same SIM card.

Will12345 · May 13, 2024, 5:26pm

After getting error The interface is connected, but the Internet can't be accessed., I logged in again a few hours later and see the router stuck on:

Connecting…

Some SIM cards have special usage restrictions, for example, the need to use a specific APN. If your SIM card cannot be registered, please check with your network operator to see if your SIM has any special restrictions.

At this point, the AXT1800 needs to be rebooted for internet connection to come back. The GL-M2 DOES NOT need to be rebooted.

Will12345 · May 13, 2024, 5:29pm

I have also applied this fix - Spitz x3000 - potential bug in modem.sh check_ip() to the GL-AXT1800.

By changing 0.0.0.0 to "0.0.0.0", but it did not help because AT+CGPADDR command did not return any 0.0.0.0 IP address.

Will12345 · May 14, 2024, 1:30am

Encountered the same The interface is connected, but the Internet can't be accessed. after a few hours of rebooting the AXT1800 router.

I tried running the following:

ifdown modem_2_1
ifup modem_2_1

The commands ran successfully, but the connection seems stuck with:

Connecting…

Some SIM cards have special usage restrictions, for example, the need to use a specific APN. If your SIM card cannot be registered, please check with your network operator to see if your SIM has any special restrictions.

Only a reboot of the AXT1800 would bring up the internet connection from GL-M2 (RM520N).

ywp · May 14, 2024, 1:32am

gl_modem -B 1-1 AT AT+CGPADDR
ubus call network.interface.modem_1_1_4 status | jsonfilter -e ‘@[“ipv4-address”][0].address’

When something goes wrong, look at the results of these two commands

Will12345 · May 14, 2024, 3:23am

When I encounter the issue The interface is connected, but the Internet can't be accessed., then running the provided commands provide:

root@GL-AXT1800:~# gl_modem -B 2-1 AT AT+CGPADDR

AT+CGPADDR
+CGPADDR: 1,"28.164.123.230","38.7.251.145.44.14.88.166.10.210.81.81.128.37.212.22"
+CGPADDR: 2,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 3,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 4,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 5,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 6,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"

OK
root@GL-AXT1800:~# ubus call network.interface.modem_2_1_4 status | jsonfilter -e '@["ipv4-address"][0].address'
28.167.156.170

After rebooting the AXT1800 router and re-executing the commands, I get the following:

root@GL-AXT1800:~# gl_modem -B 2-1 AT AT+CGPADDR

AT+CGPADDR
+CGPADDR: 1,"28.181.185.60","38.7.251.145.44.32.129.186.10.210.81.81.154.35.155.13"
+CGPADDR: 2,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 3,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 4,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 5,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 6,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"

OK
root@GL-AXT1800:~# ubus call network.interface.modem_2_1_4 status | jsonfilter -e '@["ipv4-address"][0].address'
28.181.185.60

I see that the IP address DO NOT MATCH when the issue occurs. When the connection is alive, then I see the IP address MATCH.

Will12345 · May 14, 2024, 3:24am

These are the logs when the issue occurs:

Mon May 13 22:17:43 2024 user.notice mwan3[10613]: Execute ifdown event on interface modem_2_1 (wwan0)
Mon May 13 22:17:44 2024 user.notice firewall: Reloading firewall due to ifdown of modem_2_1 (wwan0)
Mon May 13 22:17:44 2024 user.notice nat6: Firewall config="cfg02dc81" zone="lan" zone_masq6="0".
Mon May 13 22:17:44 2024 user.notice nat6: Firewall config="cfg03dc81" zone="wan" zone_masq6="1".
Mon May 13 22:17:44 2024 user.notice nat6: Found firewall zone_name="wan" with zone_masq6="1" zone_masq6_privacy="1".
Mon May 13 22:17:44 2024 user.notice nat6: Setting up masquerading nat6 for zone_name="wan" with zone_masq6_privacy="1"
Mon May 13 22:17:44 2024 user.notice nat6: Ensuring ip6tables chain="zone_wan_postrouting" contains our MASQUERADE.
Mon May 13 22:17:44 2024 user.notice nat6: Ensuring ip6tables chain="zone_wan_input" contains our permissive DNAT rule.
Mon May 13 22:17:44 2024 user.notice nat6: Ensuring ip6tables chain="zone_wan_forward" contains our permissive DNAT rule.
Mon May 13 22:17:44 2024 user.notice nat6: Found device="wwan0" for network_name="modem_2_1".
Mon May 13 22:17:44 2024 user.notice nat6: Enabling IPv6 temporary addresses for device="wwan0".
Mon May 13 22:17:44 2024 user.notice nat6: Accepting router advertisements on wwan0 even if forwarding is enabled (required for temporary addresses)
Mon May 13 22:17:44 2024 user.notice nat6: Using temporary addresses for outgoing connections on interface wwan0
Mon May 13 22:17:44 2024 user.notice nat6: Done setting up nat6 for zone="wan" on devices: wwan0
Mon May 13 22:17:44 2024 user.notice nat6: Firewall config="cfg18dc81" zone="guest" zone_masq6="0".
Mon May 13 22:17:45 2024 user.info mwan3track[14696]: Detect ifdown event on interface modem_2_1 (wwan0)
Mon May 13 22:17:50 2024 user.notice mwan3track[14696]: Interface modem_2_1 (wwan0) is offline

I no longer see any logs after the last line.

ywp · May 14, 2024, 3:54am

Can I debug it? A faulty machine

Will12345 · May 14, 2024, 4:00am

Ok. How to allow you to debug?

ywp · May 14, 2024, 4:03am

use goodcloud or use todesk

Will12345 · May 14, 2024, 6:41pm

I have sent you the GL cloud information.

Will12345 · May 14, 2024, 9:24pm

@ywp - The no connection on GL-M2 issue occurred again.

I ran the following commands:

gl_modem -B 2-1 AT AT+CGPADDR

ubus call network.interface.modem_2_1_4 status | jsonfilter -e '@["ipv4-address"][0].address'

The ubus command did not have the IP address. We do not have this issue on our GL-X3000-5G on firmware 4.4.8.

ywp · May 15, 2024, 2:43am

The script for detecting ip changes on the M.2 development board has been fixed
Test whether it is repaired or not, please let me know,thank you

Will12345 · May 15, 2024, 2:52am

Can you let me know which script that is? I would like to save a backup.

ywp · May 15, 2024, 3:09am

/lib/functions/modem.sh

Will12345 · May 15, 2024, 11:13am

This issue seems resolved. I now see this in the logs:

Tue May 14 22:44:36 2024 user.notice root: modem ip different, now regain ip ...
Tue May 14 22:44:36 2024 daemon.info avahi-daemon[4486]: Withdrawing address record for 192.0.0.2 on wwan0.
Tue May 14 22:44:36 2024 daemon.info avahi-daemon[4486]: Leaving mDNS multicast group on interface wwan0.IPv4 with address 192.0.0.2.
Tue May 14 22:44:36 2024 daemon.info avahi-daemon[4486]: Interface wwan0.IPv4 no longer relevant for mDNS.
Tue May 14 22:44:36 2024 daemon.notice netifd: Interface 'modem_2_1_4' has lost the connection
Tue May 14 22:44:36 2024 daemon.notice netifd: Interface 'modem_2_1_4' is now down
Tue May 14 22:44:36 2024 daemon.notice netifd: Interface 'modem_2_1_4' is disabled
Tue May 14 22:44:36 2024 daemon.notice netifd: Interface 'modem_2_1_4' is enabled
Tue May 14 22:44:36 2024 daemon.notice netifd: Interface 'modem_2_1_4' is setting up now
Tue May 14 22:44:36 2024 daemon.notice netifd: modem_2_1_4 (15616): udhcpc: started, v1.33.2
Tue May 14 22:44:36 2024 daemon.notice netifd: modem_2_1_4 (15616): udhcpc: sending discover
Tue May 14 22:44:36 2024 user.notice mwan3[15594]: Execute ifdown event on interface modem_2_1_4 (unknown)
Tue May 14 22:44:36 2024 daemon.notice netifd: modem_2_1_4 (15616): udhcpc: sending select for 192.0.0.2
Tue May 14 22:44:36 2024 daemon.notice netifd: modem_2_1_4 (15616): udhcpc: lease of 192.0.0.2 obtained, lease time 7200
Tue May 14 22:44:36 2024 daemon.info avahi-daemon[4486]: Joining mDNS multicast group on interface wwan0.IPv4 with address 192.0.0.2.
Tue May 14 22:44:36 2024 daemon.info avahi-daemon[4486]: New relevant interface wwan0.IPv4 for mDNS.
Tue May 14 22:44:36 2024 daemon.info avahi-daemon[4486]: Registering new address record for 192.0.0.2 on wwan0.IPv4.
Tue May 14 22:44:36 2024 daemon.notice netifd: Interface 'modem_2_1_4' is now up
Tue May 14 22:44:37 2024 user.notice firewall: Reloading firewall due to ifdown of modem_2_1_4 ()

Will12345 · May 15, 2024, 11:58am

@ywp - I just encountered this same issue again where the GL-M2 connection encounters:

The interface is connected, but the Internet can't be accessed.

I ran these commands:

root@GL-AXT1800:~# gl_modem -B 2-1 AT AT+CGPADDR

AT+CGPADDR
+CGPADDR: 1,"28.193.239.143","38.7.251.145.44.168.89.52.10.210.81.87.153.211.36.92"
+CGPADDR: 2,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 3,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 4,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 5,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"
+CGPADDR: 6,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"

OK
root@GL-AXT1800:~# ubus call network.interface.modem_2_1_4 status | jsonfilter -e '@["ipv4-address"][0].address'
28.193.239.143

The IP address both matches, so your last fix on /lib/functions/modem.sh was able to refresh the IP address.

But this new issue is coming up when I do the following:

Macbook connect to AXT1800 router. Internet works.
Connect to GlobalProtect VPN (work VPN) from Macbook. Internet stop working after connection to work VPN.
GL-M2 connection on AXT1800 router encounters The interface is connected, but the Internet can't be accessed. Internet failovers to Repeater.

@ywp - why does GL-M2 connection break after I connect to work VPN? After failover to repeater, the internet works again and I can connect to work VPN from Macbook on repeater connection. Please check GL cloud (same MAC ID and login password).

The issue seems to only occur after I connect to work VPN. I am connecting to VPN from the Macbook and not on AXT1800.

The exact same scenario DOES NOT occur on my GL-X3000-5G on firmware 4.4.8.

Will12345 · May 15, 2024, 5:01pm

If I set the repeater as priority connection, then I can access the internet on Macbook after logging into GlobalProtect VPN (VPN from device, not router).

If I set cellular as priority connection, then cellular will lose connection AFTER I login to GlobalProtect VPN (using IPSec protocol) from the device. The router failover to repeater connection and internet is restored after failover. Cellular connection remains The interface is connected, but the Internet can't be accessed.

Will12345 · May 15, 2024, 11:26pm

If I downgrade AXT1800 firmware to 4.2.3, then the Macbook can connect to GlobalProtect VPN with cellular connection as priority on AXT1800. The router remains connected on cellular.

I think something broke in firmware 4.4.6+. This is not an issue with my X3000 on firmware 4.4.8.

Will12345 · May 16, 2024, 1:01am

@ywp - should we replace all get_modem_bus calls in /lib/functions/modem.sh with get_modem_bus "usb"?