[Pdns-users] Reverse lookup problem

[bdushok at luzerne.edu]

I'm encountering a problem with reverse lookups that I've been having 
difficulty troubleshooting.   I'm using PDNS 2.9.16.

Forward lookups always work.  When I perform reverse lookups they only 
work if I connect directly to my servers.

To troubleshoot I've dialed into my ISP and performed a lookup as follows:


svcr-205-238-247-78:~ bob$ dig www.luzerne.edu

; <<>> DiG 9.2.2 <<>> www.luzerne.edu
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43167
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 2

;; QUESTION SECTION:
;www.luzerne.edu.               IN      A

;; ANSWER SECTION:
www.luzerne.edu.        3117    IN      A       199.224.108.38

;; AUTHORITY SECTION:
luzerne.edu.            165011  IN      NS      NS1.luzerne.edu.
luzerne.edu.            165011  IN      NS      NS2.luzerne.edu.
luzerne.edu.            165011  IN      NS      NS-1.EPIX.NET.

;; ADDITIONAL SECTION:
NS1.luzerne.edu.        1953    IN      A       199.224.108.100
NS-1.EPIX.NET.          80146   IN      A       199.224.86.20

;; Query time: 183 msec
;; SERVER: 199.224.86.16#53(199.224.86.16)
;; WHEN: Wed Jul  6 15:23:05 2005
;; MSG SIZE  rcvd: 144


This is correct, 199.224.108.38 is www.luzerne.edu.

I've now tried a reverse lookup:

svcr-205-238-247-78:~ bob$ dig -x 199.224.108.38

; <<>> DiG 9.2.2 <<>> -x 199.224.108.38
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 10139
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

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

;; Query time: 181 msec
;; SERVER: 199.224.86.16#53(199.224.86.16)
;; WHEN: Wed Jul  6 15:23:13 2005
;; MSG SIZE  rcvd: 45

Nothing!  I'll try both lookups via my nameserver at 199.224.108.100:

svcr-205-238-247-78:~ bob$ dig @199.224.108.100 www.luzerne.edu

; <<>> DiG 9.2.2 <<>> @199.224.108.100 www.luzerne.edu
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44329
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.luzerne.edu.               IN      A

;; ANSWER SECTION:
www.luzerne.edu.        3600    IN      A       199.224.108.38

;; Query time: 166 msec
;; SERVER: 199.224.108.100#53(199.224.108.100)
;; WHEN: Wed Jul  6 15:23:23 2005
;; MSG SIZE  rcvd: 49

Looks fine.  Lets try a reverse lookup.....

svcr-205-238-247-78:~ bob$ dig @199.224.108.100 -x 199.224.108.38 

; <<>> DiG 9.2.2 <<>> @199.224.108.100 -x 199.224.108.38
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43857
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

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

;; ANSWER SECTION:
38.108.224.199.in-addr.arpa. 3600 IN    PTR     www.luzerne.edu.

;; Query time: 201 msec
;; SERVER: 199.224.108.100#53(199.224.108.100)
;; WHEN: Wed Jul  6 15:23:35 2005
;; MSG SIZE  rcvd: 74

If this were a nameserver problem how would it have worked when I accessed 
my server directly? 

Any suggestions would be appreciated.

Thanks,
Bob