GL-Mifi LAN question


If I were to convert the WAN port to a second LAN port per the instructions in this thread:

Will the router then act like a 2-port ethernet switch (plus wifi AP)?

Some background about my application:

I would be using this in an industrial setting. All devices have static IP addresses. I need to set up the wifi router “in-line” as follows: Customer ethernet network (wired only) –> RJ-45 network jack –> wifi router –> 5-port un-managed ethernet switch –> Four ethernet devices (wired only). Will my four devices still be able to talk to the customer ethernet network? In this setup, one of GL-Mifi LAN connections goes to the network jack, and the other goes to the 5-port switch.

The goal is to be able to set up the ethernet devices from a phone/tablet app on site - thus the need for a wifi AP. Once the device setup is complete, then the idea would be to remove the GL-Mifi from the network, and connect the 5-port switch directly into the RJ-45 network jack. The technician needs to be right next to the four devices to perform the setup, as there are some physical aspects to the setup.

Thanks in advance for any help/advice.

Converting the WAN to LAN will not by itself solve your issue. The device is configured as a router and the LAN will have it’s own DHCP server and be configured to serve addresses in the 192.168.8.X subnet (out of the box). I would expect that you will have a conflict of some type with the primary DHCP server\LAN, which is probably on another subnet.

If the devices to be set up do not need to talk to the rest of the network during setup you can plug the LAN into the switch and NOT connect the MIFI to the main network. You would need to change the default IP address of the MIFI’s LAN to that of the customers network which would require a reboot of the MIFI. You may not need to make the WAN a LAN.

If you need to access to the balance of the LAN during config, then you want to convert the MIFI to a "dumb AP’ where you disable the DHCP server and change the LAN protocol from static to DHCP. The later will cause the MIFI and your wireless devices to get an IP address from the primary router DHCP pool.

You could leave the protocol as static and manually assign an IP from the customers subnet, but you would need to know this info. I consider the later a “safer” solution, as there is always an IP on the device and you can SSH in. Setting the LAN protocol to DHCP will leave the device with no IP if booted unconnected to a LAN as there is no active DHCP server.

The former can be done in the GLi GUI. The later I expect will require the use of the OpenWrt GUI, and may not be easy to do on a phone. If you do go down this route however there is a theme called Material which works reasonably well on a good smart phone (not so good on an old iPhone). Not sure if it’s in packages or if you need to find the forum link.

I think it is quite simple by following the links. DHCP will not be an issues as the WAN port (eth0) is bound to lan and DHCP is not enabled. So just try it.


Thanks very much for the replies.

I don’t necessarily need to be able to set up the mifi from a phone/tablet - we will almost always have a laptop available for that purpose. A phone/tablet will be much easier to handle for our device setup though, because we sometimes have to install hundreds of devices, and carrying a laptop all over a facility (particularly in the environments we work in) is very cumbersome.

I need the devices to be able to talk to the rest of the network during setup. My preference would be to assign a static IP to the Mifi (whether or not this requires disabling DHCP) so that it acts as a “dumb” AP . I always receive a list of allocated and free IP addresses from the customer prior to installation, so there is no problem doing this.

Thanks again for the help.

There is a wiki for this. It is a combo of CLI and editing configs, but you can do all in Luci.

If you consider the MIFI a “tool” then you should be able to set it up once and just change the devices IP as you move from client to client. If you also want it to double as a true router, then it may be best to create 2 config files and do a backup and restore.

In routine operation I will set an expectation that for the dumb AP you will not be able to use the GL GUI tools, but need to use Luci to change the device IP. May be wrong, but you would have to test it.


Great, thanks for link. I haven’t spent a lot of time yet with OpenWRT, but I’m not too concerned about using Luci to change the device IP, because it would only need to be done once at the beginning of each installation job - but thank you for the heads-up.