Take the 2-minute tour × # netstat -at Active Internet
connections (servers and established) Proto Recv-Q Send-Q Local
Address           Foreign Address         State tcp        0
0 localhost:30037         *:*                     LISTEN tcp
0      0 localhost:ipp           *:*                     LISTEN
tcp        0      0 *:smtp                  *:*
LISTEN tcp6       0      0 localhost:ipp           [::]:*
LISTEN  What does the asterisk * in *:smtp mean ?  Why is there
no IP address shown?  share|improve this question  1 Answer 1
up vote 2 down vote accepted  It is a wildcard meaning "any".
For example, in the third line:  tcp        0      0 *:smtp
*:*                     LISTEN  The first *, in *:smtp, means
the process is listening on all of the IP addresses the machine
has. The second *, in *:*, means connections can come from any
IP address. The third *, in *:*, means the connection can
originate from any port on the remote machine.  sh