GL-MT3000 for isolated video intranet, no WAN

I have a small isolated network I create with some POE network cameras. I want to use the GL-MT3000 to provide DHCP IP addresses to the connected cameras, all client devices that would connect to the network either using WiFi (provided by the GL-MT3000) or connected to the isolated network. This all works great, but for clients (iPads) that connect to this isolated network by ethernet, I’d like them to be able to also connect to the public internet over WiFi. Since the GL-MT3000 forces a gateway and router IP address to the iPad clients, the iPads can’t connect to the internet over WiFi.

How do I configure the GL-MT3000 to not send a gateway/router IP address to clients connected over ethernet?

Even if I would not recommend changing it, here you go:

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I saw that post, but I couldn’t figure out how to implement those suggestions in the UI. Can you help me with that?

You can’t use the UI for that. Time to go with SSH :wink:

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I’m comfortable going with SSH, but what I’m asking is once I connect to the GL-MT3000 over SSH, what do I do then? What files do I modify and with what?

Mostly following the content within the link:

Building off of Daniel B’s answer, for OpenWRT, modify /etc/config/dhcp to add the appropriate options:

config dnsmasq
    # To disable setting the default gateway
    option dhcp_option '3' 

    # To disable setting the DNS server
    option dhcp_option '6' 

I attempted to do that already, but the file /etc/config/dhcp was not there. Should I just create a new file called “dhcp” in that directory and have it contain just that config dnsmasq?

Are you sure that the file isn’t there? Would be strange.
How did you check that?

Here is the situation - I’m creating a product that I will sell to swim coaches that consists of a small pelican case (which encloses electronics) and some underwater POE network cameras. Swim coaches will set this case on a pool deck, plug it in to power, plug in the underwater cameras, and then connect to the system with one or more iPads to view cameras, record, etc. Here is a diagram:

Wireless Network Diagram Template (1)

In this diagram, everything enclosed inside the box (what I call the Recording “Hub”) is isolated from the internet. The hub includes a POE switch, a Raspberry Pi running my headless network video recording application, and your GL-MT3000 acting as a DHCP server and a WiFi access point. There is no WAN cable connected to this - it is a completely isolated “intranet”.

The normal use case is for coaches to connect their iPads to the SSID that is broadcast by the GL-MT3000 and then run my iOS app that allows them to view cameras, make/edit recordings, etc. While they are doing this, they have no internet connection at all.

The use case I am trying to figure out now is when a coach needs to simultaneously connect to this isolated hub as well as the public internet. For things like drones, GoPro cameras, etc., I know that an iPhone can connect to a drone or a GoPro over WiFi, but the iPhone knows that there is no internet connection involved, so the iPhone will ask the user if they want to use the cellular network for internet access. I want to do a similar thing - have an iPad connect to the isolated hub using a USB-C-Ethernet dongle (connecting over Ethernet), but then also connect to a public WiFi to access the internet.

I believe I am being blocked from doing this because the GL-MT3000 is setting a router/gateway to all devices connected using DHCP, so the iPad only recognizes the hard-wired network interface.

My bad - the file is indeed there! Sorry about that!

I tried adding these two lines to the dhcp file, and the router is still sending the “router” address to the iPad/iPhone (see picture). When connected to this isolated network, I have no connection to the internet, which I need:

Some devices, maybe iOS as well, will set the DHCP server as router if there is no router option sent by dnsmasq. Imho: Trying to avoid that the gateway is sent via DHCP isn’t the solution to your problem.

I don’t really understand the problem anyway, tbh. Routing should be totally capable of doing whatever you need. The biggest issue might be using 2 NICs within the iPad - maybe this does not work at all.

I want an iPad to be able to simultaneously connect to an isolated (non-WAN connected) video camera network, as well as to the internet through either WiFi (if the iPad is connected to the isolated video network over ethernet) or cellular network.

Think about it this way - imagine you are on your phone and you connect to a GoPro camera over wifi to download videos. This doesn’t preclude the iPhone from connecting to the internet at the same time. This is what I want to do - but instead of a GoPro, it is a small isolated network of multiple video cameras.

Can’t you just use the block WAN feature on the cameras? And still have Internet on the mt3000?

I am not convinced that iPads can use two different networks simultaneously. Did you check that this is the case?

In a normal world, you would simply connect the MT3000 to the internet and put the cams behind a dedicated network + firewall rules. So the iPad would just connect to the MT3000 and is able to access the internet + the dedicated firewall zone.

From my point of view, it does not make sense to connect 1 device to two networks at the same time, you need a router for that and, happily, the MT3000 is a router. :partying_face:

Thank you for your comments. It isn’t possible for the MT3000 to be connected to the WAN in our current system.

All I’m trying to do is to have the MT3000 present itself to a connected device just like a GoPro or a drone does - where it is clear to the client that the connection is not connected to the internet and another internet connection should be used. I know this is possible since I use my iPhone with a drone and a GoPro all the time.

Would be interesting if the iPhone still has Internet via WiFi while using it with GoPro.

I would assume it does not.

In my case, when I connect to the GoPro (or a drone) over WiFi, my iPhone will tell me that there is no internet connection and ask if I want to keep trying WiFi or use cellular data. In the case of an iPad that is connected to the MT3000 by ethernet, I am hoping that the iPad will notice that the ethernet connection is not connected to the internet and ask me if it should use WiFi (or cellular, if the iPad is cellular equipped) for an internet connection. I am not entirely sure about this, but I believe that the iPhone knows that there is no internet connection because no gateway or router is sent over with the DHCP address from the GoPro. This is why I’m asking if the MT3000 can be configured like this.

The iPhone checks the internet connection by using some techniques that are far behind “checking if there is a default gateway”. So this issue isn’t solvable by adjusting the router, sorry. It’s a client-side thing .