ifconfig output: ipv4 netmask format

[Warner Losh]

On Apr 8, 2011, at 1:00 PM, Sergey Vinogradov wrote:

> 08.04.2011 19:55, Mike Bristow пишет:
>> On Fri, Apr 08, 2011 at 07:40:56PM +0400, Sergey Vinogradov wrote:
>>> On 08.04.2011 19:23, Warner Losh wrote:
>>>> On Apr 8, 2011, at 6:08 AM, Sergey Vinogradov wrote:
>>>> If we really wanted to make it human readable, we'd output 10.2.3.4/24
>>> 
>>> So, maybe, while following the POLA, we should add an option, as Daniel
>>> mentioned above? To output the CIDR?
>> 
>> Non-contigous netmasks are legal in IPv4.  What do you do if someone adds
>> the CIDR flag but the netmask cannot be represented in CIDR notation?
> 
> And boom goes the dynamite. Reverting to my first proposal about changing only netmask notation.

Non-contiguous netmasks are *not* legal anymore in IPv4.  They have gone the way of the dodo.  While some stacks still support it, a growing number of an interesting number of bugs with them that actual deployments with non-contiguous submasks becomes more hassle than it is worth.

Warner