RT-N66U Merlin F/W Repeater Wrong Gateway IP

[freddie802]

I have an RT-N66U running the latest Merlin firmware connecting it to a Comcast Gateway. I successfully connected the 5Ghz band of the RT-N66U to the 5Ghz band on the Comcast Gateway in repeater mode. I can connect successfully to either of my repeated SSID's either on the 2.4Ghz or the 5Ghz band and get a valid IP address. The issue I am having is that the gateway IP the is received via DHCP either on the 2.4Ghz or 5Ghz is the IP for the RT-N66U repeater and not the IP for the comcast gateway. If I create a static IP everything works fine.

Comcast IP 10.0.0.1

Asus IP 10.0.0.66 gotten via DHCP

DHCP address via DHCP is 10.0.0.177 with gateway IP 10.0.0.66 instead of 10.0.0.1.

If I create a static IP changing the gateway IP to 10.0.0.1 the repeater works on both bands.

Is there a known fix for this or is this a bug in the firmware?

 

[Nullity]

Is the Asus still acting as a router?

Edit: Can you more clearly explain your network topology?

 

[freddie802]

Sure, I have a Comcast Gateway that has both a cable modem, 4 port switch and dual band wifi. The ssid of the 2.4Ghz band is x-2.4, the ssid of the 5Ghz band is x-5 on the Comcast Gateway. It acts as the primary router. I have the Asus RT-N66U configured as a repeater not bridge and getting an IP via DHCP. The Asus IP is 10.0.0.66 and the IP of the Comcast Gateway is 10.0.0.1. I have the Asus connecting to the Comcast on the 5Ghz band to the ssid x-5 and the ssid that it broadcasts is x-5Ext. The ssid on the Asus 2.4Ghz band that it broadcasts is x-2.4Ext and it isn't doesn't connect to the Comcast Gateway at all via wireless.
Comcast broadcasts x-2.4 & x-5 as ssids
Asus connects to Comcast via 5Ghz repeater using x-5 and broadcasts x-2.4Ext & x-5Ext

When a wireless client connects to either x-2.4Ext or x-5Ext the following lease is obtained:
IP 10.0.0.177
Mask 255.255.255.0
Gateway IP 10.0.0.66
DNS 75.75.75.75

The problem is that the Gateway should be 10.0.0.1 and when I do the same thing making it a static gateway of 10.0.0.1 instead of 10.0.0.66 everything works fine.

 

[outrage_uk]

As you know from my post, I have a similar issue with the AC68U.

I get the same behaviour when setting "Obtain IP address automatically", from within the Repeater Mode config screen (after you connect to host wireless network). The repeater (wrongly) acts as gateway and doesn't give out the correct address.

On my set up, when connecting to a 5 Ghz host - If you manually set the IP address for the repeater, it doesn't seem to forward DHCP requests at all, and clients do not get an IP. This maybe worth trying, as you have static IP's set up?

Could you try and connect to your Comcast 2.4 Ghz as host network to test? My AC68U works as it should (forwards DHCP requests to the gateway which gives out the lease), but in my situation the 2.4 Ghz network is too slow, and would need 5 Ghz working - but at least wireless clients can connect with correct IP for now.