What are the key lengths of these algorithms that Observium uses? I have some firewalls, which require to set explicitly which algorithm they have to communicate with Observium. However, I cannot make it work, even though I tried all the key lengths on my firewalls. I am having trouble using SNMP v3 on the following devices:

HardwareSummit X440-48t
Operating SystemExtreme XOS 15.3.1.4 patch1-19 (nossh) 

HardwareSummit X440-24t
Operating SystemExtreme XOS 15.3.1.4 patch1-19 (nossh) 

HardwareSummit Stack V2
Operating SystemExtreme XOS 15.3.1.4 patch1-41 (nossh) 

HardwareASA5515
Operating SystemCisco ASA 9.2(2)4 

Observium does report that it could not authenticate. SNMP v2c works though.