Cisco Catalyst 3650 Series Manual page 31

Chapter 2 Switch Installation
Figure 2-4
connections. This stack provides only half bandwidth and does not have redundant connections.
Figure 2-4
Figure 2-5
Figure
does not have redundant connections. In
two stacks, and the top and bottom switches become the active switch in the stack. If the bottom switch
is a member (not active or standby switch), it reloads.
Figure 2-5
Figure 2-6
Power-On Sequence for Switch Data Stacks
Consider these guidelines before you power on the switches in a stack:
•
•
If changes are made to the stack without powering down the switches, the following results can occur:
OL-29734-01
shows an example of a stack of Catalyst 3650 switches with incomplete StackWise cabling
Example of a Data Stack with Half Bandwidth Connections
PWR-C2-250WAC
1
PWR-C2-250WAC
PWR-C2-250WAC
2
and Figure 2-6 show data stacks of Catalyst 3650 switches with failover conditions. In
2-5, the StackWise cable is bad in link 2. Therefore, this stack provides only half bandwidth and
Example of a Data Stack with a Failover Condition
PWR-C2-250WAC
1
PWR-C2-250WAC
2
PWR-C2-250WAC
3
Example of a Partitioned Data Stack with a Failover Condition
PWR-C2-250WAC
1
PWR-C2-250WAC
PWR-C2-250WAC
2
The sequence in which the switches are first powered on might affect the switch that becomes the
active switch and the standby switch.
There are two ways to elect an active switch:
– If you want a particular switch to become the active switch, configure it with the highest
priority. Among switches with same priority, the switch with the lowest MAC address becomes
the active switch.
If you want a particular switch to become the active switch, power on that switch first. This
–
switch remains the active switch until a reelection is required. After 2 minutes, power on the
other switches in the stack. If you have no preference as to which switch becomes the active
switch, power on all the switches in the stack within 1 minute. These switches participate in the
active switch election. Switches powered on after 2 minutes do not participate in the election.
PWR-C2-640WAC
PWR-C2-640WAC
PWR-C2-640WAC
Figure 2-6, link 2 is bad. Therefore, this stack partitions into
PWR-C2-640WAC
PWR-C2-640WAC
PWR-C2-640WAC
PWR-C2-640WAC
PWR-C2-640WAC
PWR-C2-640WAC
Catalyst 3650 Switch Hardware Installation Guide
Planning a Switch Data Stack
2-7