Fixing "Device Denied SNMP Access" Traps in HPE IMC

IMC needs correct SNMP credentials to read the MIBs on each device. When they’re wrong, you’ll see traps like these:

Trap Name:    Device Denied SNMP Access
Severity:     Major
Trap Time:    2016-05-30 19:41:43
Description:  Device "My Network Switch" denied access.

iMC:             10.0.10.10
Trap of Source:  MYSWITCH (10.0.10.254)
Location:        Home
Contact:         "Network Admins"
Trap Name:       Authentication Failure
Severity:        Warn
Trap Time:       2016-05-31 07:15:23
Description:     Device receives an SNMP message with an erroneous community string

These are almost always the device (switch, firewall and so on) refusing IMC’s requests. Check the device’s own logs and you’ll usually find the failures line up with IMC’s polling times.

How to fix it #

1. Check the credentials in IMC for the device: the SNMP settings, and the SSH username and password.
2. Remove the write community from the IMC configuration if the device only has read-only SNMP configured.
3. Test SNMP from the IMC server itself using the Net-SNMP tools. Install them on the IMC server, then query the device from a command prompt:

snmpwalk -v 2c -c public 10.0.10.254

If the walk fails, the problem is on the device. Check its SNMP configuration against the vendor’s documentation, or see SNMPv3 on ArubaOS-Switch.

To manage credentials for many devices at once, use access parameter templates.