Configuring a device for SNMP

This will cover setting up SNMPv2 and SNMPv3 and adding these devices into Cisco Prime 2.2


What is SNMP? According to Cisco documentation, SNMP is "an application layer protocol, facilitates the exchange of management information among network devices, such as nodes and routers. It comprises part of the TCP/IP suite. System administrators can remotely manage network performance, find and solve network problems, and plan for network growth by using SNMP."

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/managed_services/8_6_1/cucm/managed_services/snmp.html

What are trap logs? Traps are messages that are recorded and then they get reported in real time as the events occur. These traps are ususally sent via SNMP to a network monitoring server like Cisco WCS or Cisco Prime.

Few common traps:
* reports of rogue APs
*Aps with excessive client loads
*interference or noise
*coverage holes detected
CleanAir events

Trap types can be configured in the WLC under Management --> SNMP --> Trap Controsl page.

Syslog and SNMP? What is the difference?
You dont have to use both. Syslog is on port 514 UDP while SNMP traps are on port 162 UDP

SNMP traps can relate to the events you want to see that is being triggered on the device without having to turn on debug for everything.

SYSLOG will send anything that you can see on the CLI of the device at whatever the level you have set for logging.

Simply put, syslog sends system messages to a logging server. It will send messages from time to time while SNMP will send a message if you have a trap setup specifically.  SNMP is more secure. SNMP can be used to pull statistics and network utilization from interfaces.

http://www.cisco.com/en/US/technologies/collateral/tk869/tk769/white_paper_c11-557812.html#wp9000392
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Setting up SNMPv2 on the WLC (read-only):
snmp community create mysnmpv2ro
snmp community ipaddr 192.168.1.1 255.255.255.0 mysnmpv2ro
snmp community accessmode ro mysnmpv2ro
snmp community mode enable mysnmpv2ro

*note: The IP address is the IP of the prime server

Setting up SNMPv2 on the WLC (read-write):
snmp community create mysnmpv2rw
snmp community ipaddr 192.168.1.1 255.255.255.0 mysnmpv2rw
snmp community accessmode rw mysnmpv2rw
snmp community mode enable mysnmpv2rw

Setting up SNMPv2 on a Switch:
snmp-server community mysnmpv2rw rw
snmp-server location los angeles
snmp-server contact info@lperera3.blogspot.com
snmp-server chassis-id cisco4500-switch

configuring to send alerts:
snmp-server host 192.168.1.1 version 2c mysnmpv2rw
snmp-server enable traps snmp linkdown linkup coldstart warmstart
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Setting up SNMPv3 on a Switch:
snmp-server user snmpv3username snmpv3groupname v3 auth authpwd123 priv aes 256 privpwd123

snmp-server user snmpv3username snmpv3groupname v3 auth md5 authpwd123 priv des privpwd123

Tie it to an ACL:
snmp-server user snmpv3username snmpv3groupname v3 auth md5 authpwd123 priv des privpwd123 acc 10

ip access-list standard 10
permit 192.168.1.1

show commands:
show snmp user
show access-list 10

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Setting up SNMPv3 on the WLC:

config snmp v3user create mysnmpv3 rw hmacsha aescfb128 authkey123 encryptkey123
config snmp version v3 enable
config snmp v3user delete default