[j-nsp] EX4200 resilience (VC vs 10GB cross-connect)

[Cord MacLeod]

On Jan 13, 2010, at 12:55 PM, Ross Vandegrift wrote:

> 
>> In terms of software upgrades - is it possible to upgrade one member
>> at a time (as you would in a non-VC setup) so as to not interrupt
>> connectivity from the access\rack switches?
> 
> Nope - you have to upgrade the whole chassis and reboot it when you do
> an upgrade.  This works quite smoothly.

It isn't possible to upgrade one member at a time when it's live, correct.  However when you plug in a new member to your VC that isn't running the correct version of code, you can upgrade that one from the existing VC on the fly with no disruptions.

> 
>> Are there any other situations\operations on a VC that would take
>> both switches offline - further making it more sense to either have
>> two switches, or two sets of 2 members VCs?
> 
> JUNOS bugs - by far, the #1 source of downtime in our EX4200s VCs.
> If your aggregation layer is supposed to be HA, I'd keep the two
> apart.

I have a two member VC as an agg layer.  It's been up and running for over 6 months with zero issues in production.  As Ross says, make sure your JUNOS is recommended and stable.