DNS reply issue

metallica1973 · 07-04-2007, 09:18 PM

I have a bind caching server setup up at my office and it works fine. Everytime I attempt to ping my RADIUS server I get a reply but from the wrong machine instead of from the actual machine that I am looking for a response from!. So that you have a better picture:

peon >------------------> pings >--------------------------> RADIUS

idiot <-----------------------< replies <-----------------------<RADIUS

so when I recieve my reply it is comming from a completly different machine. Where in my bind data files should I be looking for a correction?

acid_kewpie · 07-05-2007, 02:23 AM

well firstly, is this DNS of is it IP? if your DNS record resolves to the wrong IP address, then change the A record for that host. if it's the right IP address then check the physical hosts. what makes you think that this wrong host replies though? you're going to get an icmp echo reply back from an ip, not a hostname, so you ping command will be doing a reverse lookup (PTR) on that IP address to turn it back into a hostname, so maybe your A's an PTR's are wonky there.

metallica1973 · 07-06-2007, 08:07 AM

UK rocks,

this is what is happening:

PHP Code:



[user@Server ~]$ ping zeos 
PING zeos.Calexica.com (192.168.3.5) 56(84) bytes of data. 
64 bytes from [B]Sludge.Daman.com [/B](192.168.3.5): icmp_seq=1 ttl=64 time=1.03 ms 
64 bytes from [B]Sludge.Daman.com[/B] (192.168.3.5): icmp_seq=2 ttl=64 time=0.300 ms 
64 bytes from [B]Sludge.Daman.com [/B](192.168.3.5): icmp_seq=3 ttl=64 time=0.307 ms 
64 bytes from [B]Sludge.Daman.com [/B](192.168.3.5): icmp_seq=4 ttl=64 time=0.296 ms 
64 bytes from [B]Sludge.Daman.com [/B](192.168.3.5): icmp_seq=5 ttl=64 time=0.308 ms 
64 bytes from [B]Sludge.Daman.com [/B](192.168.3.5): icmp_seq=6 ttl=64 time=0.263 ms 
64 bytes from [B]Sludge.Daman.com[/B] (192.168.3.5): icmp_seq=7 ttl=64 time=0.301 ms 
64 bytes from [B]Sludge.Daman.com[/B] (192.168.3.5): icmp_seq=8 ttl=64 time=0.314 ms 
 
--- zeos.Calexica.com ping statistics --- 
8 packets transmitted, 8 received, 0% packet loss, time 6998ms 
rtt min/avg/max/mdev = 0.263/0.390/1.032/0.243 ms 
[user@server ~]$

Sludge is a completly different machine that has nothing to due with Zeos. Why am I even getting a name back from the ping?

acid_kewpie · 07-06-2007, 08:13 AM

looks a lot like a mismatch A vs PTR. maybe there are two PTR records and it's picking the first one it gets? what does a "host 192.168.3.5" show?

metallica1973 · 07-09-2007, 10:44 AM

PHP Code:



[user@server ~]$ host 192.168.3.5
5.3.168.192.in-addr.arpa domain name pointer Sludge.Daman.com.
[user@server ~]$

so it must be the A vs PTR mismatch. I will check it out. Does that sound right?