Forum Discussion

barneyrudd_8217's avatar
barneyrudd_8217
Icon for Nimbostratus rankNimbostratus
Feb 03, 2012

GTM: named daemon listening on port 53 instead of GTM???

Hi,

 

 

We are using the F5 GTM for intelligent DNS load balancing.

 

 

The named daemon listens on port 53 and catches all DNS traffic, I would have expected to see the GTM process listening instead. How is the interaction done between named and the GTM process so that a decision can be made if the GTM should intercept the DNS request (or not)?

 

 

 

This seems to indicate two possibilities:

 

1) The named binary has been modified by F5

 

2) There is a redirection in the named.conf

 

 

 

Here's what I'm basing my analysis on :

 

 

[root@pradnspub01:Active] config netstat -anp|awk '/:53/'

 

tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 1414/named

 

tcp 0 0 127.1.1.1:38324 127.1.1.2:53 ESTABLISHED 1088/gtmd

 

tcp 0 0 ::1:53 :::* LISTEN 1414/named

 

udp 0 0 127.0.0.1:53 0.0.0.0:* 1414/named

 

udp 0 0 ::1:53 :::* 1414/named

 

[root@pradnspub01:Active] config

 

 

 

Thanks in advance.

 

basic
getting started
new to f5
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Feb 03, 2012
    Hi barneyrudd,

     

     

    netstat doesn't show the virtual servers or listeners which TMM uses to handle DNS queries. TMM / GTM do answer queries and only hand off to BIND if configured to do so.

     

     

    You can use b conn or tmsh show sys conn to check for connections to the virtual servers / WIPs / listeners.

     

     

    Aaron
  • barneyrudd_8217's avatar
    barneyrudd_8217
    Icon for Nimbostratus rankNimbostratus
    Feb 06, 2012
    Hi,

     

     

    Thanks for the response and information, I've realised that I misinterpreted the netstat output, the named daemon wasn't listening on all interfaces it was actually only listening on the IPV6 loopbackaddress (::1)

     

     

    ==> udp 0 0 ::1:53 :::* 1414/named