IPSocket.getaddress giving unexpected IP address

ruby-talk
1

Hi,

In the below code :

arup@linux-wzza:~> irb
2.0.0-p451 :001 > require 'socket'
=> true
2.0.0-p451 :002 > IPSocket.getaddress("localhost")
=> "::1"
2.0.0-p451 :003 >

Why am I getting "::1" instead of "127.0.0.1" ? Took the example from the doc
- http://ruby-doc.org/stdlib-1.9.2/libdoc/socket/rdoc/IPSocket.html

···

--

Regards,
Arup Rakshit

2

localhost is the host name used to communicate via network services to
your own computer, through the loopback interface. Its IP is defined
in your OS hosts file (/etc/hosts). For example, an extract of mine:

$ cat /etc/hosts
127.0.0.1 localhost
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback

2.0.0-p195 :001 > require 'socket'
=> true
2.0.0-p195 :002 > IPSocket.getaddress("localhost")
=> "127.0.0.1"
2.0.0-p195 :003 > IPSocket.getaddress("ip6-localhost")
=> "::1"

Jesus.

···

On Mon, May 12, 2014 at 4:18 PM, Arup Rakshit <aruprakshit@rocketmail.com> wrote:

Hi,

In the below code :

arup@linux-wzza:~> irb
2.0.0-p451 :001 > require 'socket'
=> true
2.0.0-p451 :002 > IPSocket.getaddress("localhost")
=> "::1"
2.0.0-p451 :003 >

Why am I getting "::1" instead of "127.0.0.1" ? Took the example from the doc
- Class: IPSocket (Ruby 1.9.2)

3

Here is mine, which is a bit odd :

arup@linux-wzza:~> cat /etc/hosts

···

On Monday, May 12, 2014 05:49:11 PM Jesús Gabriel y Galán wrote:

$ cat /etc/hosts
127.0.0.1 localhost
# The following lines are desirable for IPv6 capable hosts

::1 ip6-localhost ip6-loopback

2.0.0-p195 :001 > require 'socket'
=> true
2.0.0-p195 :002 > IPSocket.getaddress("localhost")
=> "127.0.0.1"
2.0.0-p195 :003 > IPSocket.getaddress("ip6-localhost")
=> "::1"

#
# hosts This file describes a number of hostname-to-address
# mappings for the TCP/IP subsystem. It is mostly
# used at boot time, when no name servers are running.
# On small systems, this file can be used instead of a
# "named" name server.
# Syntax:
#
# IP-Address Full-Qualified-Hostname Short-Hostname
#

127.0.0.1 localhost

# special IPv6 addresses
::1 localhost ipv6-localhost ipv6-loopback

arup@linux-wzza:~> irb
2.0.0-p451 :001 > require 'socket'
=> true
2.0.0-p451 :002 > IPSocket.getaddress("localhost")
=> "::1"
2.0.0-p451 :003 > IPSocket.getaddress("ip6-localhost")
=> "67.215.65.132"
2.0.0-p451 :004 >

--

Regards,
Arup Rakshit