On 10/29/25 02:04, Jakub Kicinski wrote:

On Mon, 27 Oct 2025 10:22:29 +0200 Ido Schimmel wrote:

quoted

This patchset extends certain ICMP error messages (e.g., "Time
Exceeded") with incoming interface information in accordance with RFC
5837 [1]. This is required for more meaningful traceroute results in
unnumbered networks. Like other ICMP settings, the feature is controlled
via a per-{netns, address family} sysctl. The interface and the
implementation are designed to support more ICMP extensions.

Is there supposed to be any relation between the ICMP message attrs
and what's provided via IOAM? For interface ID in IOAM we have
the ioam6_id attr instead of ifindex.

Would it make sense to add some info about relation to IOAM to the
commit msg (or even docs?). Or is it obvious to folks more familiar
with IP RFCs than I am?

cc: Justin

I concur with what Ido said in his reply. There is no direct relation 
between them, unfortunately. The interface ID in IOAM context could be 
totally different, although one could see the benefit of having the same 
value.