2 Replies Latest reply: Nov 27, 2012 10:58 PM by prbsparx
sebby71 Level 1 Level 1 (0 points)


having a weird issue with my DNS.  i have a machine running mountain lion with osx server.  Whenever i log into one of the laptops (also running mountain lion), and i try to ping the server, the machine resolves to the external IP of the server.  if i flush dns, it resolves to the internal IP.  If I logout or reboot, it goes back to pointing to the external IP.  i've done no modifications to the /etc/hosts.  this has me stumped.  here is what it looks like (i changed the names and ips):


rmbp15:~ admin$ ping server

PING mydomain.com ( 56 data bytes

Request timeout for icmp_seq 0

Request timeout for icmp_seq 1


--- mydomain.com ping statistics ---

3 packets transmitted, 0 packets received, 100.0% packet loss


rmbp15:~ admin$ sudo killall -HUP mDNSResponder



rmbp15:~ admin$ ping server

PING server.mydomain.com ( 56 data bytes

64 bytes from icmp_seq=0 ttl=64 time=1.209 ms

64 bytes from icmp_seq=1 ttl=64 time=1.237 ms

64 bytes from icmp_seq=2 ttl=64 time=5.686 ms


--- server.mydomain.com ping statistics ---

3 packets transmitted, 3 packets received, 0.0% packet loss

round-trip min/avg/max/stddev = 1.209/2.711/5.686/2.104 ms


This happens every time, so hosts cant connect to the server internally...  Any help would be greatly appreciated.



Mac mini, OS X Mountain Lion (10.8.2), os x server
  • UncleSally6789 Level 1 Level 1 (0 points)

    I'm not as familiar with OS X server as Windows server but it sounds like there might be a DNS record for your external IP in the DNS configuration... I would look for it in the Server Admin GUI and remove it if it exists..  then flush the DNS cache on the server.


    I would also check the laptop's network configuration under ADVANCED... see what is in the DNS records for the connection you are using. Delete the external DNS record if there is one and make sure your internal DNS record is showing up there.

  • prbsparx Level 1 Level 1 (30 points)

    That is a strange DNS issue... The only thing I can think of is that when you logout the DNS server changes. Do you have some sort of RADIUS authentication on your network where users have to authenticate to the network to gain access to internal hosts, but can access external hosts without authenticating? If so, that could be causing the problem.