I first noticed this on my local network, and see the same thing on my Linode. Apparently ns1.theplanet.com (and ns2) are reporting at least the 192.168.1.1-255 as *.static.theplanet.com. For example:

zero:~$ dig 6b.1.a8c0.static.theplanet.com A

; <<>> DiG 9.5.1-P3 <<>> 6b.1.a8c0.static.theplanet.com A
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56900
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0

;; QUESTION SECTION:
;6b.1.a8c0.static.theplanet.com.   IN   A

;; ANSWER SECTION:
6b.1.a8c0.static.theplanet.com.   84995 IN A   192.168.1.107

;; AUTHORITY SECTION:
1.a8c0.static.theplanet.com. 84995 IN   NS   ns2.theplanet.com.
1.a8c0.static.theplanet.com. 84995 IN   NS   ns1.theplanet.com.

;; Query time: 0 msec
;; SERVER: 74.207.241.5#53(74.207.241.5)
;; WHEN: Wed Oct 14 02:42:52 2009
;; MSG SIZE  rcvd: 100

6c.1.a8c0.static.theplanet.com returns 192.168.1.108, etc. I know this isn't really a problem (for me), but I don't like my local workstation telling me it's $HOSTNAME is 6b. Is this just a DNS error at theplanet.com that should clear up when someone gets around to fixing it?

Errm, ThePlanet's forums might be a better place to ask about their network...

But we're not customers of ThePlanet...

It certainly looks like he's a customer of ThePlanet to me. He's got a hostname from ThePlanet and is reporting issues with ThePlanet's name servers...

But his resolver is:

SERVER: 74.207.241.5#53(74.207.241.5)

Which is resolver1.fremont.linode.com

I get the same result (192.168.1.107) if I query my local ISP's DNS server for 6b.1.a8c0.static.theplanet.com.

Which means (I think) that The Planet has entered reserved, private IP addresses into their live DNS. I thought you were not suppose to do that

Maybe I'm missing something, but why are you using theplanet.com's DNS servers for resolving and not linodes? The only way your workstation is going to tell you that its hostname is 6b is if it is doing a reverse lookup of 192.168.1.107. That only resolves to 6b.1.a8c0.static.theplanet.com if you are using theplanet.com's DNS servers. If you use linode's DNS, it comes back not found. Who cares if doing a forward lookup of 6b.1.a8c0.static.theplanet.com resolves to a private IP, unless you are specifically looking for it then it shouldn't effect you.

By the way, public hostnames resolving to private IPs is actually pretty common. It is not recommended because it exposes your internal network information to the world, but it is commonly done if you don't care about that and don't want the hassles of running internal private DNS servers.

Of course, these particular entries aren't exposing much of anything since they're just the IP address itself encoded into the name.

192.168.1.107 is C0 A8 01 6B in hex, thus 6b.1.a8c0.static.theplanet.com.

Maybe they have such entries to just minimize client support calls with clients that try to resolve their internal (to ThePlanet) addresses and would complain if it resulted in an error.

-- David

Thanks for the information. I'm not a customer of theplanet.com, and didn't realize public hostnames resolving to private IPs was common.