How is this possible? (WAN IP outside of DHCP range)

[dave__]

Hi everyone,

How is it possible that my RT-N66U has a WAN IP outside of the DHCP range that my modem is set to?

Here's a little background on my setup:
AT&T Uverse NVG510 Modem
-IP Passthrough enabled
-Wifi disabled

ASUS RT-N66U
-Installed Merlin 374.40 last night
-Just did a 30/30/30
-WAN is configured for "Automatic"
-Unit is in "Wireless Router" mode

My concern is that my RT-N66U has a WAN IP of 108.218.34.62. However, my modem has a set DHCP range of 192.168.0.1 to 192.168.0.1 (in other words, there is no range, only one IP available).

I currently have internet connectivity but am confused how the RT-N66U has a WAN IP outside of the DHCP range that the modem is handing out?

I"ve attached a couple of config screenshots below to help visualize.

Thanks!
Dave

 

[L&LD]

You're getting yourself confused.

The 192.168.1.1 address is not a public (WAN) address, it is a private LAN address.

There is nothing wrong with your setup. It is working as you've selected by setting it up in Bridge Mode (IP Passthrough enabled).

 

[Nerre]

My guess is that this

-IP Passthrough enabled

is the key.

Your RT-N66U most likely gets the IP address from the ISP DHCP server, the modem has no external IP (since it is set to passthrough). It does have a LAN IP so you can access the web ui.

 

[dave__]

My guess is that this

is the key.

Your RT-N66U most likely gets the IP address from the ISP DHCP server, the modem has no external IP (since it is set to passthrough). It does have a LAN IP so you can access the web ui.

Ok, great. I guess I was confused as I thought that the modem was supposed to give the router an IP within its DHCP range.

I did double-check and the WAN IP my router has is the public IP on my AT&T Modem.

Thanks for taking a look!
Dave