I am debugging some problems with postfix. When I establish a connection nothing happens and netstat
shows:
$ netstat -anp
...
tcp 0 0 129.132.202.106:25 129.132.179.232:60154 ESTABLISHED -
Why is the process missing?
lsof
does not show the established connection
$ lsof -n -i :25
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
master 6139 root 11u IPv4 472858 0t0 TCP 127.0.0.1:smtp (LISTEN)
master 20033 root 11u IPv4 523921 0t0 TCP 129.132.202.106:smtp (LISTEN)
smtpd 20042 postfix 6u IPv4 523921 0t0 TCP 129.132.202.106:smtp (LISTEN)
Traffic:
11:26:44.182443 IP 129.132.179.232.59517 > 129.132.202.106.25: S 3522488764:3522488764(0) win 65535 <mss 1460,nop,wscale 5,nop,nop,timestamp 73851028 0,sackOK,eol>
11:26:44.182831 IP 129.132.202.106.25 > 129.132.179.232.59517: S 3950923498:3950923498(0) ack 3522488765 win 5792 <mss 1460,sackOK,timestamp 18832449 73851028,nop,wscale 7>
11:26:44.183150 IP 129.132.179.232.59517 > 129.132.202.106.25: . ack 1 win 4117 <nop,nop,timestamp 73851029 18832449>
and then nothing more
How do I find out why the listening process is not there? If I attach strace
to master
nothing is shown. No activity whatsoever during the attempted connection.
Best Answer
You need to run
netstat
usingsudo
.Without root privileges,
netstat
is unable to go poking around in the processes of other users (denoted by a-
in the last column of your output), so the-p
option will only identify processes owned by you, and this process is apparently not owned by you.So the solution simply becomes: