Cisco Catalyst 3550 Series User Manual

27-7
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 27 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 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 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.

Cisco Catalyst 3550 Series Specifications

General

Form Factor	Rack-mountable
Manageable	Yes
RAM	64 MB
Device Type	Switch
MAC Address Table Size	12000 entries
Routing Protocol	RIP
Features	VLAN support
Power Supply	AC 120/230 V (50/60 Hz)
Ports	24 or 48 x 10/100Base-TX, 1 x GBIC, 2 x 10/100/1000Base-T
Operating Temperature	32 to 113°F (0 to 45°C)