[j-nsp] MX Virtual Chassis?

[Saku Ytti]

On (2013-01-10 14:53 +0000), OBrien, Will wrote:

> I'm curious if anyone has been using MX's in a VC config. It's supported on the new MPC blades, but supposedly not with the older DPCs.
> I haven't done any testing yet, just minimal research. 
> 
> Why would I want to? Well, I'm after redundancy with my services blades. Specifically, MS-DPCs. I've got a pair of 480s, each with a single MS-DPC.
> I'd be hoping to configure rsp interfaces on the VC. 

I firmly believe on average all of these software shared chassis solution
offer worse availability than single box.

Outage is most commonly caused by

1. operator
2. broken software
3. broken hardware

And FT, VSS, VPC et.al. are reducing risk 3 by increasing risk 2. This will
only decrease MTBF.

We still regularly have problems with well tested, interoperating protocols
such as BGP. I don't believe existing vendors have processes in place to
produce proprietary non-interoperating feature which isn't totally broken.

I wouldn't even do this with firewalls or any stateful fault tolerance
anywhere. Acceptable configurations
1
1+1
2+1
2+2

Most commonly deployed configuration
2

(+ -> routing separated)
(2 -> stateful fault tolerant)

-- 
  ++ytti