I just got my new LM1200 LTE modem and a T-mobile data sim card. The modem updated to new firmware without asking and now it doesn't work right. According to its web interface, it is in BRIDGE mode which is supposed to pass the public IP to the router and turn its own NAT and firewall off and let the router handle that stuff. But that isn't what is happening. While all the settings for "router" mode disappear, its still very much in router mode and the router is getting a private IP. If I google "whats my IP" it returns a public IP which is not the same as the private IP that the router gets. In the mean time, I can access public web sites, but I cannot access any of my cameras from the outside. It is blocking all incoming ports. I have tried rebooting both the modem and router and doing a factory reset - none of these things help. Anybody have an LM1200 with the same problem with the latest update? Any older updates that can be installed that work without doing an unauthorized update to the latest non-working firmware?

Most of carriers don't support remote access to your network behind the LM200. This is not the issue of LM1200. Some carriers provide the special plan with VPN support that allows user to remote access the local network. Thanks John

LM1200 Bridge mode not working | NETGEAR Communities

7 Replies

JohnPeng
NETGEAR Expert
Jan 09, 2022
Most of carriers don't support remote access to your network behind the LM200. This is not the issue of LM1200. Some carriers provide the special plan with VPN support that allows user to remote access the local network.

Thanks

John
- n4mwd
  Aspirant
  Jan 09, 2022
  JohnPeng wrote:
  Most of carriers don't support remote access to your network behind the LM200. This is not the issue of LM1200. Some carriers provide the special plan with VPN support that allows user to remote access the local network.
  
  Thanks
  John
  At this point, what I know for sure is that the modem is not working in bridge mode and not passing through the public IP. The SIM is a special data sim that is suppossed to work in both directions. So the first step is to get working LM1200 firmware that allows bridge mode to work properly.
  - JohnPeng
    NETGEAR Expert
    Jan 10, 2022
    n4mwd wrote:
    
    JohnPeng wrote:
    
    Most of carriers don't support remote access to your network behind the LM200. This is not the issue of LM1200. Some carriers provide the special plan with VPN support that allows user to remote access the local network.
    
    Thanks
    
    John
    
    At this point, what I know for sure is that the modem is not working in bridge mode and not passing through the public IP. The SIM is a special data sim that is suppossed to work in both directions. So the first step is to get working LM1200 firmware that allows bridge mode to work properly.
    
    We know that some T-Mo business plans support VPN and allow user to remote access the local network. Good luck.
    
    Thanks
    
    John
- n4mwd
  Aspirant
  Jan 09, 2022
  JohnPeng wrote:
  Most of carriers don't support remote access to your network behind the LM200. This is not the issue of LM1200. Some carriers provide the special plan with VPN support that allows user to remote access the local network.
  
  Thanks
  John
  On re-evaluation, you might be right. The modem reports the same IP address coming from tmobile that the router has. This is what one would expect in bridge mode. The public ip from whatsmyip.com, is not shown anywhere on the router which says that it might not have it.
  
  The sim card seems to be accessing the internet via a NAT, so the IP address that modem gets is a natted IP address. I will contact tmobile to see if they can supply me with a static ipv6 address. This whole thing is going to be useless to me if I can't get incomming connections to work. That is the reason I bought it.

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LM1200 Bridge mode not working