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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter28 Configuring SNMP Configuring SNMP
When configuring SNMP informs, you need to configu r e th e SNMP engine ID for the remote agent
in the SNMP database before you can send proxy requests or informs to it.
Changing the value of the SNMP engine ID has important side effects. A user's password (entered
on the command line) is converted to an MD5 or SHA security digest based on the password a nd the
local engine ID. The command-line password is then destroyed, a s required by RFC 2274. Because
of this deletion, if the value of engineID changes, the security digests of SNMPv3 users become
invalid, and you need to reconfigure SNMP users by using the snmp-server user username global
configuration command. Similar restrictions require the reconfigurat ion of community strings when
the engine ID changes.
Disabling the SNMP Agent
Beginning in privileged EXEC mode, follow these steps to disable the SNMP agent:
The no snmp-server global configuration command disables all running versions (Version 1,
Version 2C, and Version 3) on the device. No specific Cisco IOS command exists to enable SNMP. The
first snmp-server global configuration command that you enter enab les all versi ons of SNMP.
Configuring Community Strings
You use the SNMP community string to define the relationship between the SNMP manager and the
agent. The community string acts like a password to permit access to the agent on the switch. Optionally,
you can specify one or more of these characteristics associated with the string:
An access list of IP addresses of the SNMP managers that are permitted to use the commun ity strin g
to gain access to the agent
A MIB view, which defines the subset of all MIB objects accessible to the given community
Read and write or read-only permission for the MIB objects ac cessibl e t o th e c omm unit y
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 no snmp-server Disable the SNMP agent operation.
Step3 end Return to privileged EXEC mode.
Step4 show running-config Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.