Switching

Hi all, 

What is the different between MC-LAGand Virtual Chassis deployment?
Can you give a matrix table about pros and cons for each deployment above?

Thank all 🙂 

Not aware of any such table, probably because MC LAG is just a single feature which would simply be configured as an AE on the virtual chassis.

The main differences I see would be:

MC LAG only supports two devices while VC usually has 10

MC would keep configurations and all systems and management separate while VC creates a single entity with multiple line cards and dual RE.

MC-LAG is generally positioned as a 'core' technology, while VC is generally used at the edge.  VC is generally seen as "stacking", but both allow multiple switches to act as one by sharing information.

As Spuluka point out, MC-LAG is limited to 2 devices/switches, although one can inter-connect (via MC-LAG) multiple pairs of MC-LAG switches.  VC can be extended up to 10 switches (depending upon model) and with VCF up to 24 switches - VCF is VC in spin/leaf design with greater expansion over the 10 member VC limit.

When comparing it would generally be a 2-switch VC, versus a 2-switch MC-LAG.  In VC there is one control plane (redundant with multiple REs) while MC-LAG uses 2 distinct and different control planes.  Some people find different control planes as 'better' option, especially for Core devices.  This is often seen as the major difference.

Since VC has one control plane, there is a single point of management - generally makes things easier.  MC-LAG configuration is more complex, although recent SW features such as peer config sync, and others makes the config portion a lot easier.  See below for details of these changes:

https://www.juniper.net/documentation/en_US/junos/topics/concept/mc-lag-config-sync-understanding.html

Hope this may help you.  I would suggest discussing this with your Juniper partner or account team to determine which is best fit for your specific situation and the Juniper products being used.

One more thing

Virtual Chassis, you have only one Routing Engine (one master, one backup), but MC-LAG is one or two. With these ports were joined LAG, only one, but with these ports were not join LAG, they were still independent.

Virtual Chassis = Stack

MC-LAG = vPC