Juniper EX9200 Features Manual page 66

Virtual Chassis Feature Guide for EX9200 Switches
66
Table 7: Effect of Split Detection on Common Virtual Chassis Failure
Scenarios (continued)
Type of Failure
Virtual Chassis backup
router or switch (VC-B)
goes down
Virtual Chassis backup
router or switch (VC-B)
goes down
Virtual Chassis master
router or switch (VC-M)
goes down
Split Detection
Setting Results
Enabled VC-M takes
causes all line cards (FPCs) that do not
host Virtual Chassis ports to go offline.
Previous VC-B is out of service.
The
router or switch and removes it from
the Virtual Chassis until connectivity is
restored. As a result, the Virtual Chassis
is left without a master router or switch,
which halts interchassis routing and
effectively disables the Virtual Chassis
configuration.
When the failed router or switch is brought
back into service:
The mastership election algorithm is
run to determine whether the router or
switch takes a VC-M or VC-B role. The
Virtual Chassis then becomes
operational.
All subscribers can log back in to the
router or switch.
Previous subscriber state information
is not preserved.
Disabled VC-M retains VC-M role and maintains
all Virtual Chassis ports.
Previous VC-B is out of service.
Result is a single-member Virtual
Chassis consisting of only a single
VC-M. The VC-M continues to maintain
subscriber state information and route
traffic.
Split detection setting VC-B takes over VC-M role regardless
has no effect on of whether split detection is enabled or
behavior disabled.
Previous VC-M is out of service.
Result is a single-member Virtual
Chassis consisting of only a single
VC-M. The new VC-M continues to
maintain subscriber state information
and route traffic.
When the original VC-M is brought back
into service, or when the original VC-M is
replaced with a new router or switch:
Original VC-M or its replacement takes
VC-B role.
Subscribers are not affected.
(VC-L) role, which
line-card
role isolates the master
line-card
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