[157798] in North American Network Operators' Group
Re: Whats so difficult about ISSU
daemon@ATHENA.MIT.EDU (Kasper Adel)
Thu Nov 8 19:52:26 2012
In-Reply-To: <AB4074C9-7F5D-4529-8E0A-1D434B8E9D9F@gmail.com>
Date: Fri, 9 Nov 2012 02:52:09 +0200
From: Kasper Adel <karim.adel@gmail.com>
To: Phil <bedard.phil@gmail.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
What i was asking is full ISSU, even with micro code. I assume between
Major release there will be microcode upgrade most of the time.
On Fri, Nov 9, 2012 at 2:48 AM, Phil <bedard.phil@gmail.com> wrote:
> The major vendors have figured it out for the most part by moving to
> stateful synchronization between control plane modules and implementing
> non-stop routing.
>
> ALU has supported ISSU on minor releases for many years and just added
> support for major releases.
>
> The Cisco Nexus ISSU works well, I've done an upgrade on a 5K switch and
> it was completely hitless.
>
> Juniper and Cisco with the 9K have gone through some hurdles but ISSU is
> actually usable now if the software versions support it.
>
> The main remaining hurdle is updating microcode on linecards, they still
> need to be rebooted after an upgrade.
>
> Phil
>
> On Nov 8, 2012, at 6:22 PM, Kasper Adel <karim.adel@gmail.com> wrote:
>
> > Hello,
> >
> > We've been hearing about ISSU for so many years and i didnt hear that any
> > vendor was able to achieve it yet.
> >
> > What is the technical reason behind that?
> >
> > If i understand correctly, the way it will be done would be simply to
> have
> > extra ASICs/HW to be able to build dual circuits accessing the same
> memory,
> > and gracefully switch from one to another. Is that right?
> >
> > Thanks,
> > Kim
>
