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Catalyst 3750 Switch Software Configuration Guide
OL-8550-02
Chapter 31 Configuring SNMP
Configuring SNMP
•
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 and the
local engine ID. The command-line password is then destroyed, as required by RFC 2274. Because
of this deletion, if the value of the engine ID 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 reconfiguration 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 enables all versions 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 community string
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 accessible to the community
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
no snmp-server
Disable the SNMP agent operation.
Step 3
end
Return to privileged EXEC mode.
Step 4
show running-config
Verify your entries.
Step 5
copy running-config startup-config
(Optional) Save your entries in the configuration file.
