My home network has a router/NAT (WNR3500L) and a wireless repeater (WN2500RP) of the same brand (Netgear). Since the repeater has a dynamic IP, the manufacturer put in place a special web address that directly resolves to the current repeater IP. The mechanism is stated to work with the majority of routers.
Using "dig", I see that the DNS request to the special address is directly resolved by the router DNS server (Bind running on an embedded Linux); no matter from which point of the network I send the DNS request, I always get the same internal address.
Then, sniffing the wireless traffic at the repeater bootup, I only notice this traffic toward the router:
- SSDP Notify HTTP messages
- DHCP Handshake
- STP messages
So how does this work?