ping -a 10.10.10.10
Pinging 10-10-10-10.mydomain.com [10.10.10.10] with 32 bytes of data
I'd say it's a combination of two things.
- Someone has added 10.10.10.10 to your mydomain.com zone
- You have mydomain.com as a search suffix in your operating system's settings
I'd call it quite normal and everything is behaving as it should.
I tested dns and get:
WARNING: Forward-DNS does NOT match Reverse-DNS.
DNS is INCONSISTENT.
Please request your Admin or Provider to fix this.
Probably no one has added a PTR record for 10.10.10.10 in your reverse lookup zone.