Unsupported authentication protocol when using snmpv3 sha-256 with aes-256

[Joriz]

Hello all,

I'm having some difficulties with connecting Zabbix to a FortiGate.
While i'm able to read the values with snmpwalk from the CLI on the same server Zabbix is running, i'm still unable to read the values in Zabbix itself. The SNMP icon in Zabbix turns red with error message: Unsupported authentication protocol [3].

Once i set the authentication and encryption level to SHA1 and AES it works but not with SHA256 and AES.

The Fortigate SNMP is configured as follows:

• User Name: snmpmonitoring
• Security Level: Authentication + Private
• Authentication Algorithm: SHA256 + set a password
• Encryption Alogrithm: AES + set a password
• Queries = enabled + port 161
• Traps = disabled

The snmpwalk i use and also works:
snmpwalk -v3 -a SHA-256 -A mypassword -x AES -X mypassword -u snmpmonitoring -l AuthPriv myIP


The snmptools version i use:
NET-SNMP version: 5.9

The installed Zabbix packages:
ii zabbix-agent 1:5.4.9-1+debian10 amd64 Zabbix network monitoring solution - agent
ii zabbix-apache-conf 1:5.4.9-1+debian10 all Zabbix network monitoring solution - apache configuration for front-end
ii zabbix-frontend-php 1:5.4.9-1+debian10 all Zabbix network monitoring solution - PHP front-end
ii zabbix-release 1:5.4-1+debian10 all Zabbix official repository configuration
ii zabbix-server-mysql 1:5.4.9-1+debian10 amd64 Zabbix network monitoring solution - server (MySQL)
ii zabbix-sql-scripts 1:5.4.9-1+debian10 all Zabbix network monitoring solution - sql-scripts

The Linux distribution i use:
Distributor ID: Debian
Description: Debian GNU/Linux 11 (bullseye)
Release: 11
Codename: bullseye

Everything is up to date in apt update.

Any idea what i'm missing here?

[thebossman]

I am too facing the same issue, When I use AES-256 or AES-256C
You can raise a ticket out here

https://support.zabbix.com

Will let you know if I got it fixed

[thebossman]

Change the configuration in fortigate to AES256C and set the encryption algorithm to AES256C in Zabbix