Can any port in the sate of “LISTEN” be seen to the outter?

Question

I execute the command "netstat -tln" in the shell, here is what it outputs.

the 5th field is the foreign address, i dont' know what it means here. Does "0.0.0.0:" mean any address can be connected to this port without the consideration of iptables, if so what does ":::" mean?

Answer 1

The 3 Colons (:::) signifies IPv6.

The 0.0.0.0 means that a given socket is listening on all the available IP addresses the computer has available.

If you wish to not use IPv6 i believe you can remove it. Verify the Man Page but probably removing "ipv6.o"" will work.