Verify that the switch has clustering capabilities and its software meets minimum version requirements by issuing the show version command.
For example, a switch running command and member capable software would display an output of the show version command similar to this:
Switch>show version Cisco Internetwork Operating System Software IOS (TM) C3500XL Software (C3500XL-C3H2S-M), Version 12.0(5.2)XU, MAINTENANCE INTERIM SOFTWARE Copyright (c) 1986-2000 by Cisco Systems, Inc. Compiled Mon 17-Jul-00 18:29 by ayounes Image text-base: 0x00003000, data-base: 0x00301F3C
ROM: Bootstrap program is C3500XL boot loader
Switch uptime is 3 days, 1 hour, 45 minutes System returned to ROM by reload System image file is "flash:c3500XL-c3h2s-mz-120.5.2-XU.bin"
Cisco WS-C3524-XL (PowerPC403) processor (revision 0x01) with 8192K/1024K bytes of memory. Processor board ID , with hardware revision 0x00 Last reset from warm-reset
Processor is running Enterprise Edition Software Cluster command switch capable !--- This is command capable. Cluster member switch capable !--- This is member capable. 24 FastEthernet/IEEE 802.3 interface(s) 2 Gigabit Ethernet/IEEE 802.3 interface(s)
32K bytes of flash-simulated non-volatile configuration memory. Base ethernet MAC Address: 00:D0:58:68:F1:80 Configuration register is 0xF
In this output, the Cluster command switch capable and Cluster member switch capable fields show that the switch is running a software that is both command and member capable.
If the switch was only running member capable software, you would only see the Cluster member switch capable field in the output.
A switch running command capable software can also be configured as a member switch, but the switch running only member capable software can never be configured as a command switch.
Cable the switches so that the command switch will be able to discover the candidate switches that can be added to the cluster. By using Cisco Discovery Protocol Version 2, the command switch can automatically discover switches in star or daisy-chain topologies that are up to three-cluster enabled devices (three hops) away from the edge of the cluster. With 12.0(5) XU or later code, the command switch may be configured to discover switches up to seven cluster enabled devices (seven hops) away.
To enable discovery of the candidate switch up to seven hops away, issue this command on the command switch: Switch(config)#cluster discovery hop-count 7
When a switch that supports Cisco Discovery Protocol, but does not support clustering is connected to the command switch, the cluster is unable to discover candidates attached to it.
For example, the cluster builder cannot create a cluster that includes candidates connected to a Catalyst 5000 or 6000 series switch connected to the command switch.
Make sure that all of the switches are connected using those ports in the same management VLAN. Access to all the cluster management facilities is through the command switch IP address. The command switch IP address always belongs to the management VLAN, which is VLAN1 by default.
All switches within the switch cluster must have the same management VLAN as the command switch.
Note: Beginning with the 12.0(5) XP release of software for the Catalyst 2900XL and 3500XL switches, the management VLAN can be changed from the default (VLAN1). In addition, the 12.0(5) XU or later release allows the management VLAN for the entire switch cluster to be changed using a single command through the Cluster Management Suite (CMS) Web Interface.