Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual page 1075

Configuration
Copyright © 2010, Juniper Networks, Inc.
NOTE: We recommend setting identical mastership priority values for the
master and backup members for high availability and smooth transition of
mastership in case the original master becomes unavailable.
We will configure the uplink module interfaces on three of the switches as uplink VCPs.
On the EX4200-24F switch we will configure two of the network interfaces as VCPs. We
will interconnect two of the SFP uplink VCPs on SWA-0 with two of the SFP uplink VCPs
on SWA-2. Similarly, we will interconnect the two XFP uplink VCPs on SWA-1 with the
two XFP uplink VCPs on SWA-3. Finally, we will connect the two remaining SFP uplink
VCPs on SWA-0 with two network VCPs on SWA-4. As a result, three LAGs will be
automatically formed.
Figure 23 on page 971 shows the interconnections used to form LAGs using uplink VCPs
and the network VCPs after the procedure below has been completed.
Figure 23: Virtual Chassis Interconnected Across Wiring Closets to Form
LAGs
To configure the Virtual Chassis uplink module interfaces and network interfaces as
uplink VCPs and interconnect them between two wiring closets to form LAGs, perform
this task:
Chapter 38: EX4200 Virtual Chassis—Configuration Examples
971