BIND Server address not displayed
Hi guys,
I'm working with a couple of BIND servers and everything is running smoothly. I'm curious as to why the domain name of the DNS server isn't returned when I do an nslookup, the IP is returned instead:
admin@ns1:/etc/bind$ nslookup red
Server: 192.168.56.100 <-- I would have expected this to read "Server: red.binding.edu
Address: 192.168.56.100#53
Name: red.binding.edu
Address: 192.168.56.100
admin@ns1:/etc/bind$ nslookup 192.168.56.100
Server: 192.168.56.100
Address: 192.168.56.100#53
100.56.168.192.in-addr.arpa name = red.binding.edu.
Resolv.conf looks like this:
domain binding.edu
nameserver 192.168.56.100
No syslog errors appear when restarting bind. Both named.conf and the zone files return OKs when checked. For some reason it's not pulling the reverse DNS, yet a nslookup of the IP returns the PTR record.
I'm working with a couple of BIND servers and everything is running smoothly. I'm curious as to why the domain name of the DNS server isn't returned when I do an nslookup, the IP is returned instead:
admin@ns1:/etc/bind$ nslookup red
Server: 192.168.56.100 <-- I would have expected this to read "Server: red.binding.edu
Address: 192.168.56.100#53
Name: red.binding.edu
Address: 192.168.56.100
admin@ns1:/etc/bind$ nslookup 192.168.56.100
Server: 192.168.56.100
Address: 192.168.56.100#53
100.56.168.192.in-addr.arpa name = red.binding.edu.
Resolv.conf looks like this:
domain binding.edu
nameserver 192.168.56.100
No syslog errors appear when restarting bind. Both named.conf and the zone files return OKs when checked. For some reason it's not pulling the reverse DNS, yet a nslookup of the IP returns the PTR record.
ROUTE Passed 1 May 2012
SWITCH Passed 25 September 2012
TSHOOT Passed 23 October 2012
Taking CCNA Security in April 2013 then studying for the CISSP
Comments
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ChooseLife
Member Posts: 941 ■■■■■■■□□□
That is a good question, and the answer is this:
"Server" line of nslookup output shows the DNS server being queried. If you do not specify the server to query, nslookup uses the local DNS server provided by the OS (from /etc/resolv.conf on Linux). This local server is always definied by its IP address, otherwise a loop is created - one would need to resolve DNS name of the DNS server before being able to resolve any DNS name.
Your output is completely normal and shows no problems with configucation. If you want to see red.binding.edu in the server field, just explicitly tell nslookup to query it:
$ nslookup red red.binding.edu
Hope that helps“You don’t become great by trying to be great. You become great by wanting to do something, and then doing it so hard that you become great in the process.” (c) xkcd #896
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ChooseLife
Member Posts: 941 ■■■■■■■□□□
The best way to illustrate it:
0. My "local" DNS server is 8.8.8.8:
$ grep "^nameserver" /etc/resolv.conf
nameserver 8.8.8.8
Its DNS name is google-public-dns-a.google.com.
$ nslookup 8.8.8.8
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
8.8.8.8.in-addr.arpa name = google-public-dns-a.google.com.
1. Query www.google.com. without specifying DNS server:
$ nslookup www.google.com.
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Name: www.google.com.
Address: 74.125.129.147
...
2. Query www.google.com. using 8.8.8.8 as DNS server:
$ nslookup www.google.com. 8.8.8.8
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Name: www.google.com.
Address: 74.125.129.147
...
3. Query www.google.com. using google-public-dns-a.google.com. as DNS server:
$ nslookup www.google.com. google-public-dns-a.google.com.
Server: google-public-dns-a.google.com.
Address: 8.8.8.8#53
Non-authoritative answer:
Name: www.google.com.
Address: 74.125.129.147
...“You don’t become great by trying to be great. You become great by wanting to do something, and then doing it so hard that you become great in the process.” (c) xkcd #896
GetCertified4Less - discounted vouchers for certs -
wave
Member Posts: 342
Thanks. What made me question the result was page 77 of "DNS and BIND - O'Reilly 5th edition". A name server is configured and they show an nslookup to prove it's working. The output is:
% nslookup carrie
Server: toystory.movie.edu
Address: 192.249.249.3
Name: carrie.movie.edu
Address: 192.253.253.4
ROUTE Passed 1 May 2012
SWITCH Passed 25 September 2012
TSHOOT Passed 23 October 2012
Taking CCNA Security in April 2013 then studying for the CISSP