GL-MT3000 and Prolink DL-7211 tethering not working

Wheat · February 14, 2026, 9:09pm

Hello,

In my previous Mobile Router + GL-MT3000 combo setup, I'm using TP-Link M7200, its USB tethering is plug and play and no further configuration needed in the GL-MT3000, same with android devices. Then the M7200 battery dies so I bought the Prolink DL-7211 for better connectivity and for future proofing.

The Prolink DL-7211 has a RNDIS feature, when I connect it to Windows 11 via USB cable, it shows a new network adapter that uses RNDIS protocol, same with the TP-Link M7200, but when I connect it to GL-MT3000, it is detected as Cellular and gives repeated unknown error notification every few seconds.

How can I make the USB tethering work? My temporary solution for now is to set it to Repeater mode.

Error screenshot:

System Log:

Sun Feb 15 02:45:02 2026 kern.info kernel: [ 1111.121678] usb 1-1: new high-speed USB device number 5 using xhci-mtk
Sun Feb 15 02:45:03 2026 kern.info kernel: [ 1112.348518] usb 1-1: USB disconnect, device number 5
Sun Feb 15 02:45:03 2026 kern.info kernel: [ 1113.053202] usb 1-1: new high-speed USB device number 6 using xhci-mtk
Sun Feb 15 02:45:04 2026 kern.info kernel: [ 1113.727335] rndis_host 1-1:1.0 simonet: register 'rndis_host' at usb-11200000.xhci-1, RNDIS device, xx:xx:xx:xx:xx:e9
Sun Feb 15 02:46:05 2026 kern.err kernel: [ 1174.795339] WiFi@C15L1,RTMPDeletePMKIDCache() 1311: IF(2), del PMKID CacheIdx=2

Kernel Log:

[ 1111.121678] usb 1-1: new high-speed USB device number 5 using xhci-mtk
[ 1112.348518] usb 1-1: USB disconnect, device number 5
[ 1113.053202] usb 1-1: new high-speed USB device number 6 using xhci-mtk
[ 1113.727335] rndis_host 1-1:1.0 simonet: register 'rndis_host' at usb-11200000.xhci-1, RNDIS device, xx:xx:xx:xx:xx:e9
[ 1174.795339] WiFi@C15L1,RTMPDeletePMKIDCache() 1311: IF(2), del PMKID CacheIdx=2

GL-MT3000 Firmware version: 4.8.1 Stable

Product Links:
TP-Link M7200 : https://www.tp-link.com/en/home-networking/mifi/m7200/

Prolink DL-7211: https://prolink2u.com/products/dl-7211

Wheat · February 19, 2026, 2:41am

Here's the solution for someone that will encounter the similar issue.

First, check the system logs

Sun Feb 15 02:45:02 2026 kern.info kernel: [ 1111.121678] usb 1-1: new high-speed USB device number 5 using xhci-mtk
Sun Feb 15 02:45:03 2026 kern.info kernel: [ 1112.348518] usb 1-1: USB disconnect, device number 5
Sun Feb 15 02:45:03 2026 kern.info kernel: [ 1113.053202] usb 1-1: new high-speed USB device number 6 using xhci-mtk
Sun Feb 15 02:45:04 2026 kern.info kernel: [ 1113.727335] rndis_host 1-1:1.0 simonet: register 'rndis_host' at usb-11200000.xhci-1, RNDIS device, xx:xx:xx:xx:xx:e9

Make sure that there's a log like this (last line),

rndis_host 1-1:1.0 simonet: register 'rndis_host'

This indicates that the router successfully detects 4G/5G device but it didn't know what to do with it.

The simonet is the device name, the name may be different if you're using another device, in the following commands, replace it with your device name if it's different.

Then run this command:

ifconfig simonet

Make sure it has an output similar to this:

simonet   Link encap:Ethernet  HWaddr xx:xx:xx:xx:xx:EC
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

Then this command to poke the 4G/5G device to give the GL router an IP.

ifconfig simonet up && udhcpc -i simonet

It should have a similar output like this,

udhcpc: started, v1.33.2
udhcpc: sending discover
udhcpc: sending select for 192.168.2.252
udhcpc: lease of 192.168.2.252 obtained, lease time 3600
udhcpc: ip addr add 192.168.2.252/255.255.255.0 broadcast 192.168.2.255 dev simonet
udhcpc: setting default routers: 192.168.2.1

Then this command to create an interface for it and set its firewall, replace the my_device with the name you like,

uci set network.my_device=interface
uci set network.my_device.device='simonet'
uci set network.my_device.proto='dhcp'
uci commit network

uci add_list firewall.@zone[1].network='my_device'
uci commit firewall

Note: @zone[1] is almost always the 'wan' zone on GL routers

Then this command to fully apply no reboot needed,

/etc/init.d/network restart
/etc/init.d/firewall restart

Now it's done, it will not be displayed as Tethering in GL GUI and will continue to give the same error similar to my screenshot, just ignore it.

This is a one-time configuration, it will still continue to work after reboot, it will only fail when it's already working then you unplug and re-plug the USB, just reboot the GL router to fix it.