[Python-Dev] Request for comments: [issue22941] IPv4Interface arithmetic changes subnet mask

[Antoine Pitrou]

On Thu, 12 Mar 2015 12:37:16 +0000
"Loevborg, Soeren Jakob" <soeren.j.loevborg at siemens.com> wrote:
> 
> >>> import ipaddress
> >>> ipaddress.IPv4Interface('10.0.0.1/8') + 1
> IPv4Interface('10.0.0.2/32')
> >>> ipaddress.IPv6Interface('fd00::1/64') + 1
> IPv6Interface('fd00::2/128')

Given that the behaviour is unlikely to match any use case, I'd say
it's a bug.

Related issue:

>>> ipaddress.IPv4Interface('10.0.0.255/8') + 1
IPv4Interface('10.0.1.0/32')

Should the result be IPv4Interface('10.0.0.0/8')
(i.e. wrap around)? Should OverflowError be raised?

Regards

Antoine.