Cisco Systems 3750E manual Managing Switch Stacks Understanding Switch Stacks

Chapter 5 Managing Switch Stacks

Understanding Switch Stacks

–A mixed software stack with only Catalyst 3750-E switches supporting different features or only Catalyst 3750 switches supporting different features as stack members.

For example, a Catalyst 3750-E-only stack with some members running the IP base feature set, other members running the IP services feature set, and the remaining members running the advanced IP services feature set.

–A mixed hardware and software stack with the Catalyst 3750-E and 3750 switches supporting different features as stack members.

For example, a stack with the Catalyst 3750-E members running the advanced IP services feature set and the Catalyst 3750 members running the IP services software image.

For information about Catalyst 3750 switches, see the “Managing Switch Stacks” chapter in the Catalyst 3750 Switch Software Configuration Guide.

One of the switches controls the operation of the stack and is called the stack master. The stack master and the other switches in the stack are all stack members. The Catalyst 3750-E stack members use the Cisco StackWise Plus technology to work together as a unified system. Layer 2 and Layer 3 protocols present the entire switch stack as a single entity to the network.

The stack master is the single point of stack-wide management. From the stack master, you configure:

•System-level (global) features that apply to all stack members

•Interface-level features for each stack member

A switch stack is identified in the network by its bridge ID and, if it is operating as a Layer 3 device, its router MAC address. The bridge ID and router MAC address are determined by the MAC address of the stack master. Every stack member is identified by its own stack member number.

All stack members are eligible to be stack masters. If the stack master becomes unavailable, the remaining stack members elect a new stack master from among themselves. The switch with the highest stack member priority value becomes the new stack master.

The system-level features supported on the stack master are supported on the entire switch stack. If a switch in the stack is running the IP base or IP services feature set and the cryptographic (that is, supporting encryption) universal software image, we recommend that this switch be the stack master. Encryption features are unavailable if the stack master is running the IP base or IP services feature set and the noncryptographic software image.

The stack master contains the saved and running configuration files for the switch stack. The configuration files include the system-level settings for the switch stack and the interface-level settings for each stack member. Each stack member has a current copy of these files for back-up purposes.

You manage the switch stack through a single IP address. The IP address is a system-level setting and is not specific to the stack master or to any other stack member. You can manage the stack through the same IP address even if you remove the stack master or any other stack member from the stack.

You can use these methods to manage switch stacks:

•Network Assistant (available on Cisco.com)

•Command-line interface (CLI) over a serial connection to the console port of any stack member or the Ethernet management port of a stack member

•A network management application through the Simple Network Management Protocol (SNMP)

Use SNMP to manage network features across the switch stack that are defined by supported MIBs. The switch does not support MIBs to manage stacking-specific features such as stack membership and election.

•CiscoWorks network management software

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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