GL-MT300N-V2 Answering DHCP Requests on its WAN Port

Technical Support for Routers
1

I have a GL-MT300N situated behind another router connected to the WAN (i.e. cable company).
Almost all of my machines are on this network (192.168.2.0/24) created by the WAN router.
The wan port of my GL router connects to the 192.168.2.0 network (i.e the WAN router) and produces on its LAN port a LAN of 192.168.10.0/24.
The GL router is answering DNS requests placed by hosts on the WAN router’s 192.168.2.0/24 network.

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Is there any way to cause the GL-MT300N router to ignore DHCP requests that it sees on it’s WAN port?

Thank You

2

I think in the config DHCP is not listening on the WAN port.

Does the device used static IP?

3

The VPN router behind the main router uses DHCP.
The main router has a DHCP reservation of 192.168.2.10 for the VPN router.
The VPN router’s WAN port is 192.168.2.10 and it produces the network 192.168.10.0/24.
The MAC addresses corresponding to the 10.143 and the 10.135 and the 10.103 and the 2.6 IP addresseses belong to boxes on the 192.168.2.0/24 network. The only two hosts on the 192.168.10.0/24 network correspond to the 10.12 and 10.8 IP addresses. The last four in the table are not clients of this (the VPN) router. They are clients of the main router.
So I ask again;
Is there any way to cause the GL-MT300N router to ignore DHCP requests that it sees on it’s WAN port?

Thank You

4

It just looks like you connected the LAN port (not WAN port) to your main router. Can you pls check?

Did you ever change interface configurations?

5

Oh silly me.
No changes to the interface and yes the WAN port goes to the main router.
So, I pulled the LAN plug out of the VPN router. Only connection is WAN port.
I have three clients on the LAN side of the VPN router. All three disapeared from the client list.
The list still contained all of the clients on the main router’s network.
Of course I can ping all of those clients on the main network.
That is no different than being able to ping Google. Two hops to Google from the VPN router.
Ping goes out your WAN port and a reply comes back.
What I now realize is that this has nothing to do with DHCP.
It appears that the GL router behaves differently depending on the address at it’s WAN port.
If the WAN port is connected to a private address like a 192.168 or a 10. whatever, you SEE the clients on the WAN side.
If the wan port is connected to a public IP address then DON’T SHOW every computer in the world as a client.
Pretty neat, after you think about it for a while.

All for now.