RT-AC68U - DHCP Server Has Only One Server

[alon.albert]

My setup:

ISP router handles routing.
RT-AC68U is in router mode but only handles DHCP.

The reason I have this setup is that:
a. ISP router does not support DHCP Reservations
b. RT cannot handle routing because it would need to be in the same physical location as the ISP router (in a cabinet) and I don't want that.

The RT functions as an AP but because I need it to serve DHCP, I have it setup as a router.

The DHCP settings have only one DNS server configuration available. When clients get DHCP data, they have the IP of the AP as the second DNS server (10.0.0.201 in my case). This causes occasional failures in DNS because it seems that 10.0.0.201 isn't serving DNS properly for some reason.

I have my WAN configuration page on the RT is set to static IP with WAN & NAT disabled. The 2 DNS servers on the WAN page are configured properly. I'm not sure what the WAN IP Settings should be on that page because I have WAN disabled.

What I would really like to do is run in AP and enable DHCP only.

 

[LoneWolf]

My router is not in the same location as my cable modem, and is still functioning as a router. Admittedly, I had to run a 20-30' Ethernet cord from one floor to the next, but it goes direct from the modem to the router (I also have one cord going back down to the bottom floor through the same run so that I can connect a switch and have wired connections on both floors).

I don't believe you can use DHCP on the AC68U without it operating in router mode. To do this, you would probably need a more sophisticated type of router/firewall that could run in what is called "bridge" mode, which could bridge the connection between your ISP's router. WatchGuard's XTM-2 series firewalls can perform this, as well as some other routers on the market.

One other possibility --you could set up a PC internally on your network as a DHCP server. This would allow you to set reservations even with no DHCP on the RT-AC68U. Any basic PC could be set up with this; there are open-source DHCP servers for Windows or Linux.

 

[alon.albert]

Yeah, the problem is that I can only run one cable to the router and I would need 2 for this configuration to work. One from the modem to the router and one back from the router to the switch which serves the rest of the house.

Anyway, I ended up installing a DHCP server on my 24/7 Windows box. It's really a shame that the ASUS doesn't support this trivial feature though.