[SOLVED] bind server not resolving external request

bathory · 09-10-2013, 06:59 AM

Quote:

Originally Posted by anis123

Thanks a lot its working now . and Thanks once again for your precious time . can you give your email address .if i face any problem i contact you directly on your email address.

Bundle of Thanks

Glad to see you've made it. You can click on my nick on the left and send me an email if you want.
Please mark the thread as "SOLVED" from the "Thread Tools" om top of the page

Regards

anis123 · 09-11-2013, 02:56 AM

After successfully configuring bind server on centos .and its working fine .but i think it not caching the host name because

when i dig some host on first attempt it not resolving .when i enter the same command it start resolving . so help me in this regard

bathory · 09-11-2013, 03:32 AM

Quote:

Originally Posted by anis123

After successfully configuring bind server on centos .and its working fine .but i think it not caching the host name because

when i dig some host on first attempt it not resolving .when i enter the same command it start resolving . so help me in this regard

In order to test caching, dig for the same host twice and look the query time:

Code:

dig linuxquestions.org

; <<>> DiG 9.9.3-P2 <<>> linuxquestions.org

<snip>

;; Query time: 198 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Sep 11 11:27:29 EEST 2013
;; MSG SIZE  rcvd: 222

Code:

dig linuxquestions.org

; <<>> DiG 9.9.3-P2 <<>> linuxquestions.org

<snip>

;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Sep 11 11:27:32 EEST 2013
;; MSG SIZE  rcvd: 158

anis123 · 09-11-2013, 05:45 AM

on first attempt it show me this message
dig cnn.com

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> cnn.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 40296
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;cnn.com. IN A

;; Query time: 1 msec
;; SERVER: ::1#53(::1)
;; WHEN: Wed Sep 11 20:31:02 2013
;; MSG SIZE rcvd: 25

when i use the up arrow key to enter the same command that it resolve successfully . every time this happen why not resolve on first attempt

although i resolve cnn.com 3 or 4 times before that.

bathory · 09-11-2013, 06:33 AM

Quote:

Originally Posted by anis123

on first attempt it show me this message
dig cnn.com

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> cnn.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 40296
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;cnn.com. IN A

;; Query time: 1 msec
;; SERVER: ::1#53(::1)
;; WHEN: Wed Sep 11 20:31:02 2013
;; MSG SIZE rcvd: 25

when i use the up arrow key to enter the same command that it resolve successfully . every time this happen why not resolve on first attempt

although i resolve cnn.com 3 or 4 times before that.

It does that because it first uses the ipv6 loopback interface (::1) for the query. The ::1 is not in the IPs allowed recursion,. so you get a REFUSED answer.
You can add it in the "allow-recursion ..." statement, or delete ::1 from /etc/resolv.conf. Or even disable ipv6 completely if you don't need it.

anis123 · 09-11-2013, 07:44 AM

if i add in allow-recursion statement than how i allow there just i write ::1 this or some thing else

bathory · 09-11-2013, 08:16 AM

Quote:

Originally Posted by anis123

if i add in allow-recursion statement than how i allow there just i write ::1 this or some thing else

Yes, you write the ipv6 IP (::1) followed by a semicolon:

Code:

allow-recursion { 127.0.0.1;
                        10.3.20.0/24;
                        10.3.50.0/24;
                        ::1;
                       };

anis123 · 09-11-2013, 10:48 AM

thanks i think problem with ip version 6 so i add in allow-recursion .its working fine now.

anis123 · 09-13-2013, 02:27 AM

Thanks for supporting in DNS server . Now i configure Openvpn version 2.0 on centos server 6.3 .i configure it and restart the openvpn services successfully . now i want to configure it with LDAP server .and i want to authenticate users from LDAP server. your support in this regard will be highly appreciated

bathory · 09-13-2013, 04:02 AM

Quote:

Originally Posted by anis123

Thanks for supporting in DNS server . Now i configure Openvpn version 2.0 on centos server 6.3 .i configure it and restart the openvpn services successfully . now i want to configure it with LDAP server .and i want to authenticate users from LDAP server. your support in this regard will be highly appreciated

Even though this is totally unrelated and I'm not familiar with Openvpn, I'll bite and reply in your other thread

anis123 · 09-16-2013, 05:54 AM

how we can increase the caching of DNS server .and how to check how long it kept the host name in cache and we can increase the caching time and size ?

bathory · 09-16-2013, 06:53 AM

Quote:

Originally Posted by anis123

how we can increase the caching of DNS server .and how to check how long it kept the host name in cache and we can increase the caching time and size ?

Hi,

Have a look here for the options that control the dns cache.
BUT!
For the cache size leave it undefined so your caching dns uses as much of your RAM as it's available.
Also it's little you can do for the cache time, as it depends on the zone $TTL value of the authoritative dns.
E,g. you can have a max-cache-ttl of 1w (one week) while the $TTL on the authoritative dns server is 2d or less, meaning that the record on your dns will expire after that time, so it has to query again the authoritative dns for a fresh copy.