Enabled SNMP trap

[vipinrajrc]

Hi Experts,

When i configure Snmp trap in switches it is showing a list of commands, What exacatly is these are?

snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps tty
snmp-server enable traps vtp
snmp-server enable traps vlancreate
snmp-server enable traps vlandelete
snmp-server enable traps stpx
snmp-server enable traps port-security
snmp-server enable traps config
snmp-server enable traps entity
snmp-server enable traps copy-config
snmp-server enable traps fru-ctrl
snmp-server enable traps flash insertion removal
snmp-server enable traps syslog
snmp-server enable traps bridge
snmp-server enable traps envmon fan shutdown supply temperature status
snmp-server enable traps hsrp
snmp-server enable traps bgp
snmp-server enable traps pim neighbor-change rp-mapping-change invalid-pim-message
snmp-server enable traps ipmulticast
snmp-server enable traps msdp
snmp-server enable traps rtr
snmp-server enable traps vlan-membership

Does it cause more CPU utilization? Do i need to enable snmp traps to monitor network using solarwinds NPM. I have configured community string and snmpserver host address.

Thanks

Vipin

[ngakhar]

Hi Vipin,

We usually configure SNMP traps to monitor our network reachability and availability. If anything goes on Device whether it is a link down situation or any issue with protocol running on the Device. So, whenever anything goes wrong on the device it generates an SNMP Trap and notify you if you have configure SNMP-Server host to receive the notifications/traps.

To configure SNMP host command following is the command that you need to configure:

(config)#snmp-server host

E.g.:

snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart

Above trap will send you send you following information :

>Authentication : if any one tries to poll the device using wrong community string

>linkdown/linkup : if any of the interface/ports/links goes down it will notify you

snmp-server enable traps bgp

Above trap will send you traps regarding problems with BGP running on your Device

--------------------------------------------

Now I come to CPU part, yes it may spike CPU sometime if regular polling is done from the Management Server or if any MIB has long output. You can use Solarwinds NPM for the same however if it causes high cpu then you have to openup a TAC Case with NMS team to have the issue resolved.

To know more about MIB's on your device you can execute command on your Device 'show snmp mib' and can translate the MIB's using following link to know more about particular MIB :

http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en&translate=Translate&objectInput=1.3.6.1.2.1.15

Kindly let me know in case you have any other doubts.

Thanks & Regards,

Nikhil Gakhar

[dustin.peterson]

Hi Raj,

In regards to your solarwinds question. You do not need snmp traps on your devices to get solar winds to work. The only command you need is the following.

snmp-server community RO

This will set the Read-Only community string on the device.  Then in solarwinds you just need to add the device and it will ask for the community string and you just put that in. Also in solarwinds you can monitor the cpu usage and many other things to see if it gives you any issues.

Hope this helps!

[mvsheik123]

Hi Vipin,

In addition to the experts suggestion...

1. It does not generate any addl CPU utilization. I use Solarwinds Orion as Network Monitoring tool (in addition to the traps you posted) and never had any CPU hike issues because of this.

2. In addition to addting the device with 'ro' string, I always enable necessary traps on the device.  Adding the device to NMS will let you monitor stats (interface status, interface/cpu/memory usage) but for particular feature traps (ex bgp/hsrp),

you need to enable traps.

hth

MS