netstat showing multiple lines for each listening socket

[Marc]

el9 bind-9.16, maybe netstat/os?

tcp        0      0 x.x.x.x:53        0.0.0.0:*               LISTEN      46622/named
tcp        0      0 y.y.y.y:53        0.0.0.0:*               LISTEN      46622/named
tcp        0      0 127.0.0.1:53      0.0.0.0:*               LISTEN      46622/named


> -----Original Message-----
> From: bind-users <bind-users-bounces at lists.isc.org> On Behalf Of Thomas
> Hungenberg via bind-users
> Sent: Monday, 8 July 2024 10:53
> To: bind-users at lists.isc.org
> Subject: netstat showing multiple lines for each listening socket
> 
> Hello,
> 
> we have been running some BIND nameservers on Debian-based systems for
> many years.
> 
> Until (including) Debian 10 with BIND 9.11.5, netstat always showed only
> one line
> per listening socket, e.g.
> 
> tcp        0      0 10.x.x.x:53             0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 127.0.0.1:53            0.0.0.0:*
> LISTEN      1234/named
> udp        0      0 10.x.x.x:53             0.0.0.0:*
> 1234/named
> udp        0      0 127.0.0.1:53            0.0.0.0:*
> 1234/named
> 
> 
> We noticed that with Debian 11 and 12 (BIND 9.16.48 / 9.18.24), netstat
> instead
> shows multiple (on some systems four, on others up to 20) completely
> identical lines
> for each listening socket, like this:
> 
> tcp        0      0 10.x.x.x:53             0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 10.x.x.x:53             0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 10.x.x.x:53             0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 10.x.x.x:53             0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 127.0.0.1:53            0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 127.0.0.1:53            0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 127.0.0.1:53            0.0.0.0:*
> LISTEN      1234/named
> tcp        0      0 127.0.0.1:53            0.0.0.0:*
> LISTEN      1234/named
> udp        0      0 10.x.x.x:53             0.0.0.0:*
> 1234/named
> udp        0      0 10.x.x.x:53             0.0.0.0:*
> 1234/named
> udp        0      0 10.x.x.x:53             0.0.0.0:*
> 1234/named
> udp        0      0 10.x.x.x:53             0.0.0.0:*
> 1234/named
> udp        0      0 127.0.0.1:53            0.0.0.0:*
> 1234/named
> udp        0      0 127.0.0.1:53            0.0.0.0:*
> 1234/named
> udp        0      0 127.0.0.1:53            0.0.0.0:*
> 1234/named
> udp        0      0 127.0.0.1:53            0.0.0.0:*
> 1234/named
> 
> 
> We wonder what is causing this and if this is intended behaviour?
> 
> 
>     - Thomas
> 
> --
> Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe
> from this list
> 
> ISC funds the development of this software with paid support
> subscriptions. Contact us at https://www.isc.org/contact/ for more
> information.
> 
> 
> bind-users mailing list
> bind-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/bind-users