On 7/10/19 1:09 PM, Stefano Brivio wrote:
> Jan,
>
> On Wed, 10 Jul 2019 12:59:41 +0000
> Jan Szewczyk <jan.szewc...@ericsson.com> wrote:
>
>> Hi!
>> I digged up a little further and maybe it's not a problem with MTU
>> itself. I checked every entry I get from RTM_GETROUTE netlink message
>> and after triggering "too big packet" by pinging ipv6address I get
>> exactly the same messages on 4.12 and 4.18, except that the one with
>> that pinged ipv6address is missing on 4.18 at all. What is weird -
>> it's visible when running "ip route get to ipv6address". Do you know
>> why there is a mismatch there?
>
> If I understand you correctly, an implementation equivalent to 'ip -6
> route list show' (using the NLM_F_DUMP flag) won't show the so-called
> route exception, while 'ip -6 route get' shows it.
>
> If that's the case: that was broken by commit 2b760fcf5cfb ("ipv6: hook
> up exception table to store dst cache") that landed in 4.15, and fixed
> by net-next commit 1e47b4837f3b ("ipv6: Dump route exceptions if
> requested"). For more details, see the log of this commit itself.
>
ah, good point. My mind locked on RTM_GETROUTE as a specific route
request not a dump.
