Jan,
On Wed, 10 Jul 2019 12:59:41 +0000
Jan Szewczyk <[email protected]> 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.
--
Stefano
