Juniper JUNOS OS 10.3 - SOFTWARE Manual page 1061

Table 147: Components of a Virtual Chassis Interconnected Across Multiple Wiring Closets
Switch
SWA-0
SWA-1
SWA-2
SWA-3
Copyright © 2010, Juniper Networks, Inc.
the dedicated VCPs, the master detects that SWA-1 is a member of its Virtual Chassis
configuration and assigns it a member ID.
We configure SWA-2 in wiring closet B without running EZSetup by directly connecting
to the console port. If you wish, you can run EZSetup and specify identification parameters.
Later, when you interconnect SWA-2 with SWA-0, the master of the Virtual Chassis
configuration, the master overwrites any conflicting parameters.
We will use SWA-2 as the backup of the Virtual Chassis configuration. If a problem occurs
in wiring closet A, SWA-2 would take control of the Virtual Chassis configuration and
maintain the network connections. We will configure the same mastership priority value
for SWA-2 (255) that we configured for the master. Because we power on SWA-0 before
we power on SWA-2, SWA-0 has additional prioritization properties that allow it to retain
mastership of the Virtual Chassis configuration. See "Understanding How the Master in
a Virtual Chassis Configuration Is Elected" on page 928. 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. (Setting
identical mastership priority values for the master and backup members prevents the
previous master from pre-empting the master role from the new master when the previous
master comes back online.)
After we have configured SWA-2 and set one of its uplink module ports as an uplink VCP,
we will interconnect its uplink VCP with an uplink VCP on SWA-0.
Finally, we will power on SWA-3. Because SWA-3 is interconnected with SWA-2 using
the dedicated VCPs on the rear panel, the master will detect that SWA-3 is part of the
expanded Virtual Chassis configuration and assign it member ID
will configure an uplink VCP on SWA-3 through the master and interconnect that uplink
VCP with an uplink VCP on SWA-1.
Table 147 on page 965 shows the Virtual Chassis configuration settings for a Virtual Chassis
composed of member switches in different wiring closets.
Member ID
0
1
2
3
Figure 19 on page 966 shows the different types of interconnections used for this Virtual
Chassis configuration. The rear view shows the member switches within each wiring
Chapter 44: Virtual Chassis—Configuration Examples
Role and Priority
master; mastership priority
255
linecard; mastership priority
128
backup; mastership priority
255
linecard; mastership priority
128
3 . For redundancy, we
Location
Wiring closet A
Wiring closet A
Wiring closet B
Wiring closet B
965