Any non-existing hostname is resolved to the local IP address.
[root@ct ~]# telnet fdsfsdfdsfsd Trying 10.20.30.40... telnet: connect to address 10.20.30.40: Connection refused [root@ct ~]# ping fdsfsdfdsfsd PING fdsfsdfdsfsd.myserver.tld (10.20.30.40) 56(84) bytes of data. 64 bytes from ct.myserver.tld (10.20.30.40): icmp_seq=1 ttl=64 time=0.026 ms 64 bytes from ct.myserver.tld (10.20.30.40): icmp_seq=2 ttl=64 time=0.028 ms ^C
CT has the following settings:
This behavior is provided by "search domain" settings in Linux machines.
As you can see from
ping output - it tries to reach "fdsfsdfdsfsd.myserver.tld" when you ping fdsfsdfdsfsd. Domain suffix myserver.tld correctly resolves to the local host, and, in result,
ping goes to the same machine.
Double-check the search domain settings. You can explicitly set search domain to "localdomain" to avoid such behavior:
[root@ct ~]# grep ^search /etc/resolv.conf search localdomain