[157800] in North American Network Operators' Group
Re: Whats so difficult about ISSU
daemon@ATHENA.MIT.EDU (Kenneth McRae)
Thu Nov 8 19:57:55 2012
In-Reply-To: <CALb2afM1m8aLnwPSUS-4J_vOhHF2B-K8_MujAh4RwGes-adpBg@mail.gmail.com>
Date: Thu, 8 Nov 2012 16:56:41 -0800
From: Kenneth McRae <kenneth.mcrae@dreamhost.com>
To: Kasper Adel <karim.adel@gmail.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I have performed micro code upgrades using ISSU on the Juniper platform.
On Thu, Nov 8, 2012 at 4:52 PM, Kasper Adel <karim.adel@gmail.com> wrote:
> 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
> >
>
