6-5
Catalyst 2950 Desktop Switch Software Configuration Guide
78-14982-01
Chapter 6 Clustering Swit ches Planning a Switch Cluster
Note Catalyst 2950 s tandb y comm and switc hes r unning R elease 12.1(9 )EA1 or later ca n connec t to cand idate
and membe r switche s in VLANs di fferen t from the ir manage ment VL ANs.

Planning a Switch Cl uster

Anticipating conflicts and compatibility issues is a high priority when you manage several switches
through a c lust er. This sect ion descr ibe s the se gu ideli nes , r equ ireme nts , a nd caveats tha t yo u should
underst an d b efore you cre ate the cluste r:
Automatic Discovery of Cluster Candidates and Members, page 6-5
HSRP and Standby Command Switches, page 6-12
IP Addresses, pa ge 6-15
Host Na mes, pa ge 6 -16
Passwords, page 6-16
SNMP Community Strings, page 6-16
TACACS+ and RADIUS, page 6-17
Access Modes in CMS, page 6-17
Managem ent VLAN , page 6-18
LRE Profiles, pag e 6-18
Availability of Switch-Specific Features in Switch Clusters, page 6-19
Refer to the release notes for the list o f Catalyst switches e ligible for switch clustering , including whic h
ones can be com mand switc hes and whic h ones can only be member switc hes, and for the require d
software versions an d browser and Java plug-in co nfiguration s.

Automatic Discovery of Cluster Candidates and Members

The command switch uses Cisco Discovery Protocol (CDP) to discover member switches, candidate
switches , ne ighb orin g sw itch c luste rs, a nd ed ge d evices in star or ca sca ded topol ogi es.
Note Do not d isable C DP on the c omma nd swi tch, o n clust er me mber s, or on any cl uster-cap able s wit che s
that you mi ght want a comman d switch to discover. For more informat ion about CD P, see Chapter 20,
Configuring CD P.
Following these connectivity guidelines ensures automatic discovery of the switch cluster, cluster
candi date s, conn ec ted swi tch cl usters , a nd neig hbo ring edge d evices:
Discovery throug h CDP Hops, p age 6-6
Discovery thr ough N on -CDP- Cap ab le an d No nclu ster-Cap abl e D evices, p ag e 6-7
Discovery throug h the Same Man agemen t VLAN, pa ge 6-8
Discovery through Different Management VLANs, page 6-9
Discovery of Newly I nstall ed Sw it ches , page 6- 10