Re: netstat output

[Tom H <tomh0665@gmail.com>]

Israel Garcia <igalvarez@gmail.com>> wrote:
>> server:~# netstat  -tulp
>> Active Internet connections (only servers)
>> Proto Recv-Q Send-Q Local Address           Foreign Address State  PID/Program name
>> tcp   0      0      *:mysql                 *:*             LISTEN 14399/mysqld
>> tcp   0      0      server.domain.:www *:*                  LISTEN 13109/apache2
>> tcp   0      0      *:ssh                   *:*             LISTEN 1376/sshd
>> tcp   0      0      *:afs3-fileserver       *:*             LISTEN 14626/haproxy
>> tcp   0      0      localhost:11000         *:*             LISTEN 14537/ruby
>> tcp   0      0      localhost:11001         *:*             LISTEN 14540/ruby
>> tcp   0      0      *:smtp                  *:*             LISTEN 2146/master
>> tcp   0      0      localhost:11002         *:*             LISTEN 14543/ruby
>> tcp   0      0      *:2812                  *:*             LISTEN 24723/monit
>> tcp6  0      0      [::]:ftp                [::]:*          LISTEN 26779/proftpd   <--tcp6
>> tcp6  0      0      [::]:ssh                [::]:*          LISTEN 1376/sshd       <--tcp6
>> udp   0      0      *:41746                 *:*                    14626/haproxy
>> udp   0      0      *:45110                 *:*                    833/collectd

> Maybe you have to disable ipv6
> Some hints are in http://lists.debian.org/debian-user/2009/09/msg00621.html

You have to pass an ipv4-only option to sshd at startup by setting
SSHD_OPTS to "-4" in /etc/ssh to stop ssh listening on ipv6.

If your kernel is old enough to have been compiled with ipv6 as a
module then there are a few ways that you can disable ipv6 by changing
some settings in /etc/modprobe.d/ or in /etc/sysctl.conf.

You will be able to use these methods if
"grep -i ipv6 /boot/config*"
returns
"CONFIG_IPV6=m"
(and not "CONFIG_IPV6=y").

You could also load ip6tables rules to drop all ipv6 traffic.