For named, why cannot reverse lookup? where to check? 2

[zaccaz]

Hi there,

I got 2 dns servers running on linux 6, it's an appliance machine which already EOL so got no further support from vendor.

From it's own web mgmt interface, I created "A" record for my mail server, the web mgmt interface auto prompted me to create the "PTR" record. From the web mgmt interface, I clearly see there are "A" record & "PTR" record for my mail server. However if runnig nslookup, it can only resolve name to ip, but can't resolve ip to name.

Wondering what's wrong with my linux dns server? Which conf file should I check?

Many thanks!

 

[Serbtastic]

The problem lies with the authority for your IP address. They have not delegated PTR records to you, and obviously haven't created a PTR record for your IP. Take it up with your ISP.

 

[zaccaz]

hi serbtastic,

in my case maybe different, my isp already set the dns server pointing to my own dns servers, as i want full control of my dns settings.

any idea where else to check? many thanks!

 

[ChrisAC]

Have you checked the x.x.x.in-addr.arpa zone on your server? Has the zone loaded correctly? Can you dig for the IP address @ your server? What are the results? If you tell us the domain/mail server host then we can query it and see what's going on.

Chris.

**********************
Chris A.C, CCNA, CCSA
**********************

 

[zaccaz]

hi chris,

ok, the mail server is email.tccfleet.com / 203.161.233.56

btw, which file to check for the x.x.x.in-addr.arpa zone?

many thanks!

 

[ChrisAC]

Well, your reverse record on your server is correct ..

[chris@uranium chris]$ dig -x 203.161.233.56 @dns1.tccfleet.com

; <<>> DiG 9.3.1 <<>> -x 203.161.233.56 @dns1.tccfleet.com
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40570
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;56.233.161.203.in-addr.arpa.   IN      PTR

;; ANSWER SECTION:
56.233.161.203.in-addr.arpa. 86400 IN   PTR     email.tccfleet.com.

So 56.233.161.203.in-addr.arpa resolves to email.tccfleet.com which is correct. However, the reverse zone isn't delegated to your server.

[chris@uranium chris]$ dig 233.161.203.in-addr.arpa

; <<>> DiG 9.3.1 <<>> 233.161.203.in-addr.arpa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 65495
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;233.161.203.in-addr.arpa.      IN      A

;; AUTHORITY SECTION:
203.in-addr.arpa.       10800   IN      SOA     ns1.apnic.net. read-TXT-record-of-zone-first-dns-admin.apnic.net. 2005100149 7200 1800 604800 172800

So you will need to speak to your ISP to have your zone delegated to your own servers.

Chris.



**********************
Chris A.C, CCNA, CCSA
**********************

 

[zaccaz]

hi chris,

thx for your superb explanation! however my isp is not apnic.net... anyway i'll try to contact them to see what they can help

there must be a star for you! ;-)

 

[Serbtastic]

Hmm, that's what I said...

 

[ChrisAC]

That's what he said ;-)

Chris.

**********************
Chris A.C, CCNA, CCSA
**********************

 

[zaccaz]

hi serbtastic, sorry that i'm not that smart enough to clearly understand what you said, so chris' picture did help a lot to make me understand the problem

so a star for you as well !