SNMP Configuration help

[snared04drummer]

I'm reviewing the configurations of a device and I ran across some SNMP config lines that I'm not familiar with, and haven't had much luck googling (I'm admittedly not very familiar with the configuration of SNMP in general).

Can someone either give me a brief description of each line given (excluding the snmp-server community public RW line, I got that one), and/or a link where I can get more information about them?

Configuration:

SiteDistribution#sh run | i snmp
snmp-server view cutdown iso included
snmp-server view cutdown at excluded
snmp-server view cutdown snmpUsmMIB excluded
snmp-server view cutdown snmpVacmMIB excluded
snmp-server view cutdown snmpCommunityMIB excluded
snmp-server view cutdown ip.21 excluded
snmp-server view cutdown ip.22 excluded
snmp-server community public RW

As always thanks for any help, it is always welcome.

[Reza Sharifi]

It appears that in general the purpose of all these SNMP exclude commands is to prevent the router or switch from having high CPU.

Using snmp-server view Commands

Another way to avoid performance issues is to use SNMPv3 views to force the router to prematurely end queries for the route table and to respond instead with a complete message. This blocks requests to retrieve the route table (ipRouteTable) and the ARP table (ipNetToMediaTable), but allows all other requests.

The following command example creates a view named cutdown that blocks requests for the route table and the ARP table, but allows all other requests. Note that you need to substitute your own view name and community strings when you enter these commands on your router.

snmp-server view cutdown internet included

snmp-server view cutdown ipRouteTable excluded

snmp-server view cutdown ipNetToMediaTable excluded

snmp-server view cutdown at excluded

http://www.cisco.com/c/en/us/td/docs/cable/cmts/mib/12_2sc/reference/guide/ubrmibv5/ubrmib2M.html

HTH

[snared04drummer]

Alright that makes sense, but it still leaves lingering questions about the following lines:

snmp-server view cutdown iso included

snmp-server view cutdown ip.21 excluded
snmp-server view cutdown ip.22 excluded

These commands are not referenced in anyway way in that article.

[Reza Sharifi · Accepted solution]

Here is some additional info.  It all about deploy these commands to prevent high CPU

Recommendation 1: Use snmp-server view Commands

To avoid performance issues, force the router to prematurely end queries for the route table from the network management system server. Configure the router to respond with a complete message as soon as it receives the start of a request for the route table, as follows:

snmp-server view cutdown iso included

http://www.cisco.com/c/en/us/support/docs/ip/simple-network-management-protocol-snmp/7270-ipsnmphighcpu.html