Junos OS

Hi everyone!

I was reading about VC on EX and MX but I can't realize in which cases is useful. 

I hope that you can help me.

Thanks

Wow - that is a wide open question. When is VC useful.

1. Eliminate spanning tree

2. Manage multiple switches as a single entity across wiring closets or racks

3. Have multiple switches sharing redundant route engines so as to provide a more robust HA environment

Three quick little reasons why.

I wouldn't call eliminating spanning tree a quick litle reasons. It's more a mission in live of a network designer!

This solutions brief gives you some concrete examples of what Kevin outlines.

Virtual chassis is part of how Juniper makes the transition from a traditional 3 tier switching architecture to a 2 tier architecture.  This eliminates some of the interconnect ports increasing port density and making management a little simplier.

http://www.juniper.net/us/en/local/pdf/brochures/1600059-en.pdf

Thank you so much! the answers are really helpful.

I must to specify some important thing, I work for an ISP with 38k customers.

In the case of MX104 in VC, in wich cases the Slave become Master?, When the RE of the first have a problem?, When the Slave become Master, I've to change the wire/fiber to the slave?

The routing engine failover of clusters occurs when there are problems with the master.

You do not need to change cabling, the clusters are cabled so that the transition will occur automatically without any physical changes.