SNMP v3 Views?

[CiscoPurpleBelt]

If I utilize views, will it include everything except what exclude or only what I include? 

Basically I want to utilize views to prevent high CPU.

Aslo, would using 256 bit AES matter much in terms of CPU?

[Reza Sharifi]

If SNMP v3 is causing high CPU on the device, that is most likely a bug as running SNMP should not cause high CPU.

How much does the CPU go up when you enable SNMP v3?

Here is a post that may help in identifying the issue.

https://community.cisco.com/t5/networking-documents/troubleshooting-high-cpu-in-snmp-engine-process-in-ios/ta-p/3109931

HTH

[CiscoPurpleBelt]

Great!
Sorry, this is my lab however taking into consideration as I see you can configure these settings. So for fairly newer equipment, polling for everything is basically best especially if you want a lot of data about the devices?
If not setting a VIEW then it will collect/poll all data correct?
User case for Views would be something like let's say allowing another group to only see maybe bandwidth and interface statuses or something?

Also, if you don't specifically configure for traps will it automatically trap for everything?

[Reza Sharifi]

Once you configure SNMP on your device and it is communication with the monitoring system, at that time you can controlled what gets pulled from the monitoring software. So, for example, if you are using SolarWinds to monitor your devices, you can tell the software to monitor CPU, memory, Interface status, bandwidth utilization, etc.. This is all configurable from the software you are using.

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/configuration/xe-3se/3850/snmp-xe-3se-3850-book/nm-snmp-snmpv3.html

HTH

[CiscoPurpleBelt]

Oh ok so I could just change those parameters within Solarwinds.

So you mean I don't have configure the traps on the Network devices?

[CiscoPurpleBelt]

Also, is I do "show snmp" and don't see logs being sent (0 sent, 0 dropped) that means it is not working correct?

[Reza Sharifi · Accepted solution]

Before you do anything, make sure that the management application can reach (ping) the switch or router and also the switch or router can ping the management application. If ICMP is good than configure the switch or router with SNMP parameters (see the link I provided earlier for configs) and than configure the management application to pull the switch or router.

HTH

[CiscoPurpleBelt]

Documentation is a bit difficult to be sure of some things for version 3. What if there are already devices added to Solarwinds, however they are using communities, and I don't want to use communities (not sure why they are used or if it is misconfigured as I thought that only applies to V1 and 2. I just want to use SNMPv3 groups, usernames, and views. I don't want to just start removing everything added in Solarwinds, especially servers and what not, I just want to improve current SNMP configs of devices already added especially if they are not even polling properly. What is best approach on a prod network?

[Reza Sharifi]

I just want to improve current SNMP configs of devices already added especially if they are not even polling properly. What is best approach on a prod network?

If they are not polling properly than there is problem somewhere and it does not matter if they are prod or not.  If you have issues with ver 3 start with 2c and if everything works you can always go to ver 3 later. I have been using 2c for many years now with no issues.

HTH 

[CiscoPurpleBelt]

I was thinking just remove whatever device is not polling properly or at all, then removing snmp configs and then rebuilding and then re-attempting to add to Solarwinds. Authentication passwords and what not would most likely be different then from however they were configured before. This would not cause any harm or anything in theory correct?

[Reza Sharifi]

No, since the devices are not polling properly or not polling at all, it does not cause any issues. Simply remove them from SolarWinds and than reconfigure the switch with simple SNMP parameters using 2c and than add them to SolarWinds again.

If there is any issue with NPM, SolarWinds has a pretty good tech support system.

HTH