From: Paul Robinson <paul@...>
Date: 2006-04-21T02:28:53+09:00
Subject: Re: Converting IP range to array of IP's

On 20 Apr 2006, at 18:08, Peter Ertl wrote:

> lets say you have a 192.168.0.0/10 subnet:

That's CIDR.

> 192.168.1.0 (which is a subnet but no host)
> 192.168.1.255 (which is the broadcast)

That isn't.

It's a long time since I last did any proper CIDR subnetting, but if  
you really are setting things up so flat that you have a /10 then . 
1.255 isn't a broadcast address, no? You're mixing up a CIDR subnet  
mask with the notion of an old Class C there aren't you? Or am I  
completely wrong on this and my memory is playing tricks? The largest  
subnet I've dealt with in the last 5 years is a /27...

> "all ips between ip1 and ip2 where _each_ of the digits is between the
> corresponding digit in ip1 and ip2"
>
> example:
> 192.168.1.3 - 192.168.2.4:
>
> [192, 168, 1, 3]
> [192, 168, 1, 4]
> [192, 168, 2, 3]
> [192, 168, 2, 4]

What you have there is two ranges - .1.3-.1.4 and .2.3-.2.4 so I  
think if expressed as one range, I'd want to go all the way up - be  
consistent with how ranges work elsewhere in Ruby:

 > ('bar'..'bbs').to_a
=> ["bar", "bas", "bat", "bau", "bav", "baw", "bax", "bay", "baz",  
"bba", "bbb", "bbc", "bbd", "bbe", "bbf", "bbg", "bbh", "bbi", "bbj",  
"bbk", "bbl", "bbm", "bbn", "bbo", "bbp", "bbq", "bbr", "bbs"]

Incidentally, my distant memory of the subject would suggest going  
straight from a bar to a BBS often resulted in deep regret the  
following morning - best to stop when you get to BBC or even better a  
BBQ... :-)

--
Paul Robinson