Zyxcel vs Huawei and TP-Link 4G/LTE and accessibility

[TheColdy]

Hello everyone, I have come to you with a problem that I cannot solve or find a logical explanation as to why it is not working.

I have three routers from different manufacturers TP-Link, Zyxcel, Huawei - on two of them everything works fine, except TP-Link - the same SIM card is inserted in the modem as in the others, all of these devices had the PIN lock removed, so it can't be the SIM card problem.

All settings such as Port triggering are off, UpNp the same is off, no firewall on these devices was turned off, the settings are literally the same and only on the TP-Link does not allow connection, nothing connected to the MX67 and further to the MS130-24P is unreachable. When I change to Zyxcel or Huawei everything works without configuration as it should, even after pressing the hard reset button on the router.

used devices: 
ZyXel LTE3202-M430 <- works perfectly fine

TP-Link tl-mr6400 v1.0 <- dosent work at all

HUAWEI B535-232 <- works evrything fine

dhcp is running on all of these routers...

Any ideas why? there is any problem with firmware at TP-Link? 

[javalins]

Hi @TheColdy what IP subnet is the TP-Link handing out to the MX? If the subnet is the same that the TP-Link is handing out as what the MX is configured to hand out on it's LAN side, then it won't work.  All else, I would recommend reaching out to TP-Link to see if there is something modem firmware dependent.

[TheColdy]

Hi @javalins we checked this also, it was 255.255.255.0 or *.*.0.0 and still nothing happens. The internal subnet in is completely different.

[TheColdy]

Hi again, There was problem with the firmware at TP-Link. I had to roll it back to the oldest one. 

Many customers complain about lack of connection at VPN resources on my latest version of the firmware. 

So now it is working.