LM1200 Bridge mode not working

[n4mwd]

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?

[JohnPeng · Accepted solution]

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

[JohnPeng · Accepted solution]

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]

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@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

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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.

[n4mwd]

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@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

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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.

[JohnPeng]

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@n4mwd wrote:

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@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.

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We know that some T-Mo business plans support VPN and allow user to remote access the local network. Good luck.

Thanks

John

[n4mwd]

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@JohnPeng wrote:

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We know that some T-Mo business plans support VPN and allow user to remote access the local network. Good luck.

Thanks

John

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I don't think this is a business SIM.  Its a 30GB SIM that was designed for use with 4G and 5G modems.  Standard phone SIMS from T-mobile don't allow tethering and will trap traffic from anything other than a phone.  This one is data only with no phone or SMS.

Is there any reason I can't simply connect to a private or commercial VPN service?  Or some other bidirectional tunneling protocol?

I  doubt I'm the first person with this problem.  Lots of people have IP cameras and would like to log into them.

[JohnPeng]

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@n4mwd wrote:

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@JohnPeng wrote:

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We know that some T-Mo business plans support VPN and allow user to remote access the local network. Good luck.

Thanks

John

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I don't think this is a business SIM.  Its a 30GB SIM that was designed for use with 4G and 5G modems.  Standard phone SIMS from T-mobile don't allow tethering and will trap traffic from anything other than a phone.  This one is data only with no phone or SMS.

Is there any reason I can't simply connect to a private or commercial VPN service?  Or some other bidirectional tunneling protocol?

I  doubt I'm the first person with this problem.  Lots of people have IP cameras and would like to log into them.

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Definitely, you are not the first user having the issue. But this is restricted on the carrier networks. 

[n4mwd]

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@JohnPeng wrote:

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Definitely, you are not the first user having the issue. But this is restricted on the carrier networks. 

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I did check on the T-Mobile forums and people are reporting the same problem with the T-Mobile supplied modems.  The only proven cure is a VPN.  Most are using commercial VPN's, but I am assuming that a private VPN (to an office or friend's house) will also work.

So far there has been nothing said about using IPV6. I am assuming that the reason they NAT is because of the shortage of IPv4 addresses.  That isn't an issue with IPv6.

I still need to check to see if disabling Binge-On will have any effect, but I suspect not.