[c-nsp] ASR920 randomly loosing layer-2 on a port

[Shawn L]

We upgraded the 920 to 16.12.06 this morning.  No change.  Still not
learning MAC addresses on port te0/0/4.  So, back to the drawing board.

On Mon, Jul 11, 2022 at 1:31 PM Gert Doering <gert at greenie.muc.de> wrote:

> Hi,
>
> On Mon, Jul 11, 2022 at 04:47:57PM +0000, Brian Turnbow wrote:
> > > On Mon, Jul 11, 2022 at 03:59:02PM +0000, Brian Turnbow wrote:
> > > > Yep, sounds like the infamous uptime over 2 years "feature" from 3.16
> > > (something)..
> > > > Reboot and upgrade was the only way we fixed it....
> > >
> > > Uh.  Could you elaborate on what that "feature" is, exactly?
> >
> > It was the bug where after after two years of uptime
> > If an interface went down it would stick as up and not pass traffic
> > You could not provision new interfaces.
> > Counters also stopped working. (we used this to find affected units)
>
> Now THAT is interesting.  I'm a bit further distanced from day-to-day
> operations these days (otherwise I might have noticed), but indeed,
> counters didn't work anymore either.  "No traffic on this box!" which
> I know to be not true (our daily TSM backups go through there...) - and
> after reboot, "Traffic!".
>
> Very interesting.  "Interface itself" counters are all "0", but service
> instance counters (gi0/0/2 si 90) still show traffic.  So that's actually
> something our alarming could trigger on "si has > 1 Mbit, interface itself
> has 0"...
>
> [..]
> > Sounds like it may be different.
> > Did the counters work?
> > Maybe they decided to add it into 16.06 , you never know what a BU may
> decide is a must have feature....
>
> Obviously, 16.06 has much improved performance, so 2-year-bugs are now
> hit after 0.5 years already!
>
> OTOH... seems it wasn't actually 27 weeks uptime, but quite a bit more,
> which was just distorted by SNMP uptime wrapping (and our prometheus
> instance not properly distinguishing this for old data, it only recently
> learned to query that other OID).
>
> So, definitely more than 2 years, and traffic counters stopped some 5
> months
> ago...  and we did not try to actually bring up anything new since then.
>
> Yeah, thanks a lot for this information.  This will be very helpful to
> avoid needless frustration by our on-site people ("it does not link! can
> you please try a different cable?  did you get the patch right?").
>
> gert
>
> --
> "If was one thing all people took for granted, was conviction that if you
>  feed honest figures into a computer, honest figures come out. Never
> doubted
>  it myself till I met a computer with a sense of humor."
>                              Robert A. Heinlein, The Moon is a Harsh
> Mistress
>
> Gert Doering - Munich, Germany
> gert at greenie.muc.de
>