Re: Reciving multiple RAs causes NetworkManager to storm the network with RSes

[Thomas Haller <thaller redhat com>]

On Thu, 2019-02-14 at 08:25 -0500, Brian J. Murrell wrote:
> On Thu, 2019-02-14 at 13:46 +0100, Thomas Haller wrote:
> > Hi,
>
> Hi,
>
> > In 1.10.2-16.el7_5, that code looks pretty similar. NetworkManager
> > should either log
> >
> >     "router solicitation sent"
> >
> > or
> >
> >     "failure sending router solicitation: ...
> >
> > for every RS that gets send.
> >
> >
> > Possibly the logging message was suppressed by journald's
> > ratelimiting
>
> Most likely.
>
> > (as the journal would tell you, if that's the case). Make sure to
> > disable rate-limiting, see [1].
> >
> >
> > [1] 
> > https://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/contrib/fedora/rpm/NetworkManager.conf#n28
>
> Is it really necessary to actually see the messages in the journal at
> this point?  Doesn't the packet trace and CPU load of NM from my
> previous message sufficiently prove that NM is storming RSes?

Hi,


well, NetworkManager uses libndp for IPv6 neighbor discovery.


From the logs it looks like to me the IPv6 address of the sender is
indeed the instance managed by NetworkManager.


However,

1) libndp never sends RS without being told to do so (I think).

2) NetworkManager sends RS (via libndp) only at one place. It's not
clear to me how that code could be wrong so that it might result in a
flood of RS. The logfile should show whether this code is culprit or
not.


Is the issue hard to reproduce? Your efforts are appreciated!! :)


best,
Thomas

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