Why does my (home) router append a DNS suffix?

Question

I wonder if any other people have come across this. I've rented rooms in two houses this year, and they both have Sky (a UK ISP) Broadband routers. For some reason, the router I currently use hands out "home" as a DNS suffix, and the previous one handed out "home.local".

The reasoning behind this is beyond me, and infact it seems like a stupid default, because every DNS request I make will (initially) time out, twice actually. For example, see this nslookup output when I try to resolve "purple.com"

> purple.com
Server:  SkyRouter.Home
Address:  192.168.0.1

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
Non-authoritative answer:
Name:    purple.com
Address:  153.104.63.227

With Wireshark it can be seen that initially my computer tries to resolve an A record for purple.com.home, fails, tries to resolve an AAAA record (IPV6) for purple.com.home, fails. AND THEN FINALLY it gets around to looking up an A record for purple.com, which was my initial intent.

So whenever I try to make any DNS lookup, it's delayed by 2ms whilst my computer tries it's best to do what I want, but the router is ballsing stuff up.

Does anyone know what could have possibly made the Sky or the router's manufacturer think this was a good idea?

Answer 1

Manufacturers of routers have default domains builtin to prevent name resolution of unconfigured hosts or bad hostnames externally. If you use dhcp, then those "top level" domains help you to initially find machines on your local network. And you don't have to bother with ip-adresses to set up your home network. If you want do avoid that your router attaches the local top level domain, use a dot at the end, as in google.com.