WAN Port IP Addresses appear on router

[Boycha]

Hi there,

I have a strange issue on my Asus AC68u Router. This is happening on both Merlin and AsusWRT latest versions. When my router is acting as a DHCP server, it seems then my WISP devices is also getting IP addresses from my router and appear on my devices list. Not sure how this is possible? My internet connection to the WISP is going through the WAN port, Router is in Router mode and I have a public IP. But my router is handing out 192.168.100.X IP's to their devices as well.

When I use Adguard Home on a Raspberry PI as a DHCP server this is not a problem.

Is there perhaps a router setting I can change to block this?

Thank you.

 

[drinkingbird]

Hi there,

I have a strange issue on my Asus AC68u Router. This is happening on both Merlin and AsusWRT latest versions. When my router is acting as a DHCP server, it seems then my WISP devices is also getting IP addresses from my router and appear on my devices list. Not sure how this is possible? My internet connection to the WISP is going through the WAN port, Router is in Router mode and I have a public IP. But my router is handing out 192.168.100.X IP's to their devices as well.

When I use Adguard Home on a Raspberry PI as a DHCP server this is not a problem.

Is there perhaps a router setting I can change to block this?

Thank you.

192.168.100.x is a common range used by ISPs for user access to their devices. You should not use this range on your Asus for LAN, use any range other than that one. Most likely your router isn't assigning anything to the WISP devices but if they're in the same subnet as your LAN that is why they are showing up in devices list (the router is getting confused).

 

[Boycha]

192.168.100.x is a common range used by ISPs for user access to their devices. You should not use this range on your Asus for LAN, use any range other than that one. Most likely your router isn't assigning anything to the WISP devices but if they're in the same subnet as your LAN that is why they are showing up in devices list (the router is getting confused).

Thanks for the reply, I do appreciate. I also used 192.168.1.x and 192.168.10.x, maybe I should test a complete different private IP address set here.

 

[Boycha]

When I do a tracert from my network to say 1.1.1.1, their devices is 10.x.x.x. But I do have a public IP with them. What is also strange say the IP 192.168.100.100 appears on my router, when I ping that IP, nothing response back to me...

 

[drinkingbird]

Thanks for the reply, I do appreciate. I also used 192.168.1.x and 192.168.10.x, maybe I should test a complete different private IP address set here.

1 and 10 are fine (assuming there isn't an upstream router using those ranges). It is only the 100 you should avoid as most modems and carrier devices use that range for customer access. You won't see it on a traceroute, it is a management interface only.

Right now your router is getting confused since it has 192.168.100.x on it but also sees ARP out the WAN for that same range.