Cisco Systems 3550 Using SNMP to Manage Switch Clusters

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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter5 Clustering Switches
Using SNMP to Manage Switch Clusters
Using SNMP to Manage Switch Clusters
When you first power on the switch, SNMP is enabled if you enter the IP information by us ing the setup
program and accept its proposed configuration. If you di d not u se the set up progr am to en ter the I P
information and SNMP was not enabled, you can enable it as described in the “Configuring SNMP”
section on page 18-4. On Catalyst 1900 and Catalyst 2820 switches, SNMP is enabled by default.
When you create a cluster, the command switch manages the exchange of messages between member
switches and an SNMP application. The cluster software on the command switch appends the member
switch number (@esN, where N is the switch number) to the first configured read-write and read-only
community strings on the command switch and propagates them to the member switch. The command
switch uses this community string to control the forwarding of gets, sets, and g et-next messages between
the SNMP management station and the member switches.
Note When a cluster standby group is configured, the comm an d swi tch ca n cha ng e w itho ut y our
knowledge. Use the first read-write and read-only community strings to communicate with the
command switch if there is a cluster standby group co nfi gure d for the cl uste r.
If the member switch does not have an IP address, the comm and s witch r edir ect s tra ps fro m th e member
switch to the management station, as shown in Figure 5-14. If a membe r switch has its own IP address
and community strings, the member switch can send traps directly to the management station, without
going through the command switch.
If a member switch has its own IP address and community stri ngs , they can b e used i n a ddit ion to th e
access provided by the command switch. For more information about SNMP and community strings, see
Chapter 18, “Configuring SNMP.”
Figure5-14 SNMP Management for a Cluster
Trap
Trap
Trap
Command switch
Trap 1, Trap 2, Trap 3
Member 1 Member 2 Member 3
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SNMP Manager