This article explains the reason for below log noticed on the device repeatedly.

router> show log messages | match snmp

snmpd[29654]: %AUTH-5-SNMPD_AUTH_FAILURE: nsa_log_community: unauthorized SNMP community from x.x.x.x to y.y.y.y (ABC)

x.x.x.x --> From IP

y.y.y.y --> To IP (multiple values)

ABC --> Community Name

This log is observed repeatedly for same from IP and different to IPs with same community name.

Aug 22 13:18:14 xxxdist-J snmpd[11345]: SNMPD_AUTH_FAILURE: nsa_log_community: unauthorized SNMP community from 10.149.132.106 to 134.121.251.1 (public)

Aug 22 13:18:17 xxxdist-J snmpd[11345]: SNMPD_AUTH_FAILURE: nsa_log_community: unauthorized SNMP community from 10.149.132.108 to 134.121.251.1 (public)

Aug 22 13:18:21 xxxdist-J snmpd[11345]: SNMPD_AUTH_FAILURE: nsa_log_community: unauthorized SNMP community from 10.149.132.102 to 134.121.251.1 (public)

Upon checking the logs, it looks the SNMP request from x.x.x.x is sent with wrong/unauthorized community (ABC).

The configurations on the router convey that there is no community with name 'ABC' configured on it, which led to these logs being populated.

Adding correct community in the request solves the problem.

If no clients statement is configured, all clients are allowed. We recommend that you always include the restrict option to limit SNMP client access to the switch."The following statement defines all other hosts as being restricted from the xxxx community.

[edit groups global snmp community public]

user@host# set clients-list 0/0 restrict 

Once the clients are restricted the following log should be displayed.

:SNMPD_AUTH_RESTRICTED_ADDRESS: nsa_initial_callback: request from address X.X.X.X not allowed 

2024-04-03 : Article Created
2024-10-17: Add it how to block the list