[FFmpeg-devel] [PATCH v2] avformat: enable UDP IPv6 multicast interface selection using zone index

[Rémi Denis-Courmont]

Le 29 avril 2024 13:32:41 GMT+03:00, Lynne <dev at lynne.ee> a écrit :
>Apr 29, 2024, 11:56 by remi at remlab.net:
>
>>
>>
>> Le 29 avril 2024 11:20:24 GMT+03:00, Lynne <dev at lynne.ee> a écrit :
>>
>>>> >They were they deprecated?
>>>>
>>>> They caused more bugs than they solved problems (because what we need is to add IPv6 to IPv4 apps, not IPv4 to IPv6 apps).
>>>>
>> >What bugs did they cause?
>>
>> Obviously anything that assumes IPv6 semantics is prone to breaking.
>>
>>> i know they're not very well used, because the
>>>
>> >documentation is very lacking,
>>
>> No, they're not used because they are officially deprecated for 15+ years (see RFC5156).
>>
>
>The RFC says that IPv4-Compatible addresses are deprecated,
>but doesn't say that about IPv4-Mapped addresses.

Ah, yeah, the case against mapped addresses did not make it to RFC status, likely because the main author tragically died, see draft-itojun-v6ops-v4mapped-harmful.

But anyway, I am not a vendor of IP stacks. I am just the messenger here: mapped addresses are not portable and so you should not rely on them in portable code.