Get host by addr

ruby-talk
1

Hello everybody.
I am trying to do something simple.
I have an IP address and need to do a reverse DNS lookup.
However, I consistently get a "host not found" error.
I have tried this in at least 2 different machines.

What am I doing wrong?

nk@livaditis: ~ $ irb
irb(main):001:0> require 'socket'
=> true
irb(main):002:0> Socket.gethostbyaddr("75.126.252.65")
SocketError: host not found
        from (irb):2:in `gethostbyaddr'
        from (irb):2

···

from :0

2

irb(main):001:0> require 'socket'
=> true
irb(main):002:0> Socket.getaddrinfo('75.126.252.65', nil)
=> [["AF_INET", 0, "75.126.252.65-static.reverse.softlayer.com",
"75.126.252.65", 2, 1, 6], ["AF_INET", 0,
"75.126.252.65-static.reverse.softlayer.com", "75.126.252.65", 2, 2, 17],
["AF_INET", 0, "75.126.252.65-static.reverse.softlayer.com",
"75.126.252.65", 2, 3, 0]]
irb(main):003:0>

···

-----Original Message-----
From: Nikos Kanellopoulos [mailto:kanellopoulos.nikos@gmail.com]
Sent: Saturday, August 11, 2007 3:00 PM
To: ruby-talk ML
Subject: get host by addr

Hello everybody.
I am trying to do something simple.
I have an IP address and need to do a reverse DNS lookup.
However, I consistently get a "host not found" error.
I have tried this in at least 2 different machines.

What am I doing wrong?

nk@livaditis: ~ $ irb
irb(main):001:0> require 'socket'
=> true
irb(main):002:0> Socket.gethostbyaddr("75.126.252.65")
SocketError: host not found
        from (irb):2:in `gethostbyaddr'
        from (irb):2
        from :0

3

Nice! This works fine in irb.
However, it fails to do the reverse lookup from within my rails application.
It just returns the IP as the host name. Strange...

···

2007/8/12, Felix Windt <fwmailinglists@gmail.com>:

> -----Original Message-----
> From: Nikos Kanellopoulos [mailto:kanellopoulos.nikos@gmail.com]
> Sent: Saturday, August 11, 2007 3:00 PM
> To: ruby-talk ML
> Subject: get host by addr
>
> Hello everybody.
> I am trying to do something simple.
> I have an IP address and need to do a reverse DNS lookup.
> However, I consistently get a "host not found" error.
> I have tried this in at least 2 different machines.
>
> What am I doing wrong?
>
> nk@livaditis: ~ $ irb
> irb(main):001:0> require 'socket'
> => true
> irb(main):002:0> Socket.gethostbyaddr("75.126.252.65")
> SocketError: host not found
> from (irb):2:in `gethostbyaddr'
> from (irb):2
> from :0
>

irb(main):001:0> require 'socket'
=> true
irb(main):002:0> Socket.getaddrinfo('75.126.252.65', nil)
=> [["AF_INET", 0, "75.126.252.65-static.reverse.softlayer.com",
"75.126.252.65", 2, 1, 6], ["AF_INET", 0,
"75.126.252.65-static.reverse.softlayer.com", "75.126.252.65", 2, 2, 17],
["AF_INET", 0, "75.126.252.65-static.reverse.softlayer.com",
"75.126.252.65", 2, 3, 0]]
irb(main):003:0>