[Dnsmasq-discuss] Specific treatment of Class C addresses

[Wink Saville]

Sorry for the noise, but it should have been:

Based on the analysis below, IMO it's not worth it.

On Wed, Sep 25, 2024, 04:13 Wink Saville <wink at saville.com> wrote:

> Based on the analysis below it's not
> IMO it's not worth it.
>
> Also, the KB has been deleted by
> Microsoft. Here[1] is a link to an archived
> version of that article.
>
>
> [1]:https://mskb.pkisolutions.com/kb/281579
>
>
> On Wed, Sep 25, 2024, 02:31 Simon Kelley <simon at thekelleys.org.uk> wrote:
>
>> Downsides to this proposed change.
>>
>> 1) Old versions of Windows might break.
>> 2) Newer versions of windows might break - we've not done testing on
>> which do and don't.
>> 3) Other platforms which have made the same mistake might break.
>> 4) Dnsmasq installations which unkowningly rely on this behaviour in
>> other respects might break.
>>
>> Upsides to the proposed change.
>> 1) ~1% more available addresses in DHCP pools.
>> 2) A small amount of code which no longer needs maintenance.
>>
>> It's not clear to me what the balance is here. Opinions, list?
>>
>> Simon.
>>
>>
>>
>>
>> On 18/09/2024 18:22, Jan Ceuleers wrote:
>> > Dear dnsmasq community,
>> >
>> > The changelog for version 2.47 contains the following:
>> >
>> >       Don't dynamically allocate DHCP addresses which may break
>> >       Windows.  Addresses which end in .255 or .0 are broken in
>> >       Windows even when using supernetting.
>> >       --dhcp-range=192.168.0.1,192.168.1.254,255,255,254.0 means
>> >       192.168.0.255 is a valid IP address, but not for Windows.
>> >       See Microsoft KB281579. We therefore no longer allocate
>> >       these addresses to avoid hard-to-diagnose problems.
>> >
>> > Unless I'm mistaken the listed Microsoft KB applies only to Windows
>> versions that are long since past end of support. Furthermore, CIDR was
>> introduced by the IETF more than 30 years ago.
>> >
>> > I was therefore wondering whether it is time to retire the special
>> treatment of addresses ending in .0 or .255 in Class C address ranges.
>> >
>> > Many thanks, Jan
>> >
>> >
>> > _______________________________________________
>> > Dnsmasq-discuss mailing list
>> > Dnsmasq-discuss at lists.thekelleys.org.uk
>> >
>> https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss
>>
>>
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>>
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