Re: [PATCH net-next v2] seg6: add per-route tunnel source address

[Nicolas Dichtel <nicolas.dichtel@6wind.com>]

Le 13/03/2026 à 11:20, Justin Iurman a écrit :
> On Fri, Mar 13, 2026 at 9:47 AM Nicolas Dichtel
> <nicolas.dichtel@6wind.com> wrote:
>>
>> Le 13/03/2026 à 09:44, Justin Iurman a écrit :
>>> On Fri, Mar 13, 2026 at 2:02 AM Andrea Mayer <andrea.mayer@uniroma2.it> wrote:
>>>>
>>>> On Wed, 11 Mar 2026 16:28:45 +0100
>>>> Justin Iurman <justin.iurman@6wind.com> wrote:
>>
> 
> [snip]
> 
>>>> Whether to also reject link-local is debatable: ip6_forward() does
>>>> drop it, but is there a legitimate use case where a link-local tunnel
>>>> source would actually be needed?!
>>>> I'd argue we should reject link-local addresses as well.
>>>> For instance, using them as a tunnel source violates scope boundaries and
>>>> breaks ICMPv6 error reporting.
>>>
>>> IMHO, I also think we could reasonably forbid LLs.
>>
>> Why rejecting LL? It's legal to use LL as a source address of a tunnel (and
>> forwarding packets in this tunnel). Is this forbidden with srv6?
> 
> Well, this is indeed legal (at least nothing prevents it), but they're
> not routable. So question is does it make sense at all? We're talking
> about two nodes on the same layer-2 link as the only valid use-case
> here. I'm not sure it makes sense, especially in the context of SRv6.
Yes, you're probably right. I'm usually uncomfortable with a configuration being
forbidden without any real problem/reason.