Re: Whats so difficult about ISSU

[Kenneth McRae <kenneth.mcrae () dreamhost com>]

I have executed successfully on the MX960 with no issues.. EX on the other
hand, really depends on your version of JunOS.

On Thu, Nov 8, 2012 at 4:19 PM, Alex <dreamwaverfx () yahoo com> wrote:

> http://www.juniper.net/**techpubs/en_US/junos/topics/**
> concept/issu-oveview.html<http://www.juniper.net/techpubs/en_US/junos/topics/concept/issu-oveview.html>
>
> The Juniper ISSU guide.
>
> You need two things:
>
> 1. Separation of the control plane and  forwarding plane
> 2. 2 routing engines in the same chassis -- the non active RE upgrades
> first, then when its up and running the active one goes into upgrade mode
> and control fails over to the secondary RE which is running the upgraded
> version of the software.
>
> I assume it works on any vendor that has 2 REs in the same chassis and the
> fwd and control planes are separated, and there is a redundancy protocol
> running between the two REs(like Graceful Switchover on Juniper gear).
>
>
> On 11/09/2012 01:42 AM, Kenneth McRae wrote:
>
> > Juniper also offers it on the EX virtual switching platform.  Works if you
> > have the correct version of JunOS.
> >
> > On Thu, Nov 8, 2012 at 3:38 PM, Zaid Ali <zaid () zaidali com> wrote:
> >
> >  Cisco Nexus platform does it pretty well so they have achieved it.
> > > Zaid
> > >
> > > On Nov 8, 2012, at 3:22 PM, Kasper Adel 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