Security access violation issue

[smetts]

Hello there,

We have HPE Aruba 2530-24POE switches. We have random warnings sometimes that go like this:

Security access violation from [actual IP address] for the community name or user name :

What does this mean and how we can go about fixing this?

[TerjeAFK]

This look like a SNMP warning that the IP address is trying to poll the switch using the wrong community name or wrong user name (if you have setup SNMP v3). You fix it by checking the SNMP community used by all your monitoring servers for these switches.

[smetts]

I believe the string is "public" but it's always been that way, We get these warnings all the time. What's the best way to resolve this?

[TerjeAFK]

For security reasons I would recommend that you limit the public community to monitor-only access with config like this:

no snmp-server community "public"
snmp-server community "public" restricted
snmp-server community "OurCommunity" unrestricted manager

Change all your network management software to use this new community.

Then check the IP address referred to in the security warning. Is there monitoring software running there, or some kind of port scan or network discovery software?  

[smetts]

If I do this, will this stop me from monitoring this with SCOM (systems center operations manager)? I was wondering because we were planning on doing that.

[smetts]

To answer your other question, we do have Windows Defender on these workstations and we also have management agents for SCOM and SCCM on there. 

[parnassus]

You can do two things:

1. Harden your SNMP configuration, Switch side: to do that please refer to ArubaOS-Switch Hardening Guide for 16.04 (reference here).
2. Troubleshoot offending host (if any), the one that is logged by your Switch(es) with regards to SNMP security access violation messages (a propely configured NMS such as HPE IMC or Aruba AirWave will not cause those messages to appear when it connects to monitored devices, a SNMP scanner or a faulty application do [*], as example).

As example I recall a printer application (probably badly configured or unconfigured at all) flooding a network with SNMP requests with usual "public" SNMP Community name, these requests generated, Switch side, a lot of informational logs as you experienced...and that was just a client host with a famous vendor software installed along with its printer driver.

[smetts]

Is there a way to clear out those logs out without going through all of those harden instructions? Seems intensive and time consuming.

Regarding the commands listed in one of the earlier posts, are there instructions I can follow that would allow me to put those in?

[TerjeAFK]

To put in those commands you will have to connect to the switch either with a console cable or with telnet/ssh, put the switch in config mode with the command 'configure terminal' and then enter the commands. Don't forget to save the config afterwards (write memory).

[smetts]

Ah, I see. So I take it that there's no way to do this inside the GUI itself?

[TerjeAFK]

If the switch is running a fairly new firmware version there is a Configurations tab in the GUI where you can download the config file from the switch (it's in text format), make changes to it using a text editor and then upload it to the switch.

But if you have more than this one switch then I would recommend that you take some time to learn to use the CLI. It's not that difficult, and it makes your life much easier when you want to make changes or you're troubleshooting.