Open Ports in BIND

Alan Clegg Alan_Clegg at
Sun Feb 1 16:23:41 UTC 2009

Bind wrote:
> Dear Admins
> I installed Bindv9.5.1 and it works properly,,but i have some questions
> about these parameters:
> # netstat -an |grep 53 |wc
>      391    1223   20656

I think you might want to use "lsof" (or your system equivalent) to find
the open ports that are directly related to BIND.

root at yellow:~# lsof -i -n -P | grep named | grep IP
named      6043   root   20u  IPv6   17419 TCP *:53 (LISTEN)
named      6043   root   21u  IPv4   17424 TCP (LISTEN)
named      6043   root   22u  IPv4   17425 TCP (LISTEN)
named      6043   root   23u  IPv6   17426 TCP [::1]:953 (LISTEN)
named      6043   root   24u  IPv4  133746 TCP (LISTEN)
named      6043   root   25u  IPv4  646882 TCP (LISTEN)
named      6043   root   26u  IPv4  646884 TCP (LISTEN)
named      6043   root  512u  IPv6   17418 UDP *:53
named      6043   root  513u  IPv4   17423 UDP
named      6043   root  514u  IPv4  133745 UDP
named      6043   root  515u  IPv4  646881 UDP
named      6043   root  516u  IPv4  646883 UDP

(output slightly edited to fit 80 columns)

> is first number the total queries which asked from my server on port 53
> or number of sessions that stablished?

They are useless, as your method of collecting the information did not
actually gather anything that is provably related to BIND.

> # rndc status
> xxx...
> soa queries in progress: 1
> query logging is OFF
> recursive clients: 365/32668/32768
> tcp clients: 3/10000
> server is up and running

> what is the meaning of recursive clinets 365/32668?
> is 365 the number of queries which asked from my server or number of
> sessions from other clients to me?

You currently have 365 clients asking questions.

> what is the meaning of tcp clients:3?

Three clients are using TCP for some reason (zone transfer, truncation
fall-back-to-TCP, or direct TCP queries).


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: OpenPGP digital signature
URL: <>

More information about the bind-users mailing list