Mango router behind other router: access the internet, but not the devices in the first local network

[CupCake]

Hello,

using GL.iNet GL-MT300N v2:

• WAN connected to an existing network
• LAN should provide a new, isolated subnet with DHCP

Goal:

• Devices in the network on LAN port can reach the internet
• but they cannot reach the devices in the first network (besides the gateway itself)

Is this possible with standard firmware or OpenWRT? That would be the easiest way? Block routing to the subnet number one?

Thanks in advance.

[will.qiu]

Hi

This can be achieved by adding the following rule in Luci - Network - Firewall - Custom Rules:
iptables -I FORWARD -s 192.168.8.0/24 -d 192.168.1.0/24 -j DROP

Here,

• 192.168.8.0/24 is Mango's LAN subnet
• 192.168.1.0/24 is the existing network address, or Mango's WAN subnet

Please note that these should be replaced with the actual corresponding subnet.

[CupCake]

Thanks a lot! The Custom Rules tab is unfortunately missing when I access Luci > Network > Firewall.

Firmware 4.3.25

[will.qiu]

Oh, then please use the Luci > Network > Firewall > Traffic Rules > Add following firewall rule.