When using netstat on a listening port what is the difference between localhost:6666 and [::]:6666 in 'Local Address' field

Question

Using ubuntu 11.04, I run netstat -nplt the results for local address may be

localhost:6666

or

[::]:6666

What is the difference?

I believe that the [::]: binds the service at port xxxx to all interfaces, (lo, eth0, eth1 ) and localhost: only binds it to loopback interface (lo). I think I am missing something. How can I toggle between the two states?

user9517 · Answer 1 · 2013-02-14T08:55:20.747

4

localhost:6666

This is the IPv4 loopback address 127.0.0.1

[::]:6666

This means port 6666 on all IP addresses (v4 and v6).

edited Feb 14 '13 at 08:55

answered Feb 14 '13 at 08:35

user9517

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score 2 · Accepted Answer · answered Feb 14 '13 at 08:33

2

[::] is an ipv6 notation and it's the same as 0000:0000:0000:0000:0000:0000:0000:0000 , and it means any ip address.

answered Feb 14 '13 at 08:33

0wn3r

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does this server the same function as 0.0.0.0 in ipv4? Bind to all interfaces? – Dave Feb 14 '13 at 08:34
Does it bind to ip addresses or interfaces – Dave Feb 14 '13 at 08:36
Yes, it's bind to all ip address, so all interfaces – 0wn3r Feb 14 '13 at 08:38
Found a good explanation here: http://serverfault.com/questions/78048/whats-the-difference-between-ip-address-0-0-0-0-and-127-0-0-1 – Dave Feb 14 '13 at 08:41

When using netstat on a listening port what is the difference between localhost:6666 and [::]:6666 in 'Local Address' field

2 Answers2