[SNMP4J] SNMPv3 "discovery"

[Marco.Bresciani at alcatel-lucent.it]

Hello all,
  I've received a "specification" document that states the following:

Automatic detection of SNMP Operating mode
At manager side the detection of SNMP operating mode to activate the 
correct SNMP protocol is performed by sending the Request of discovery 
SNMPv3 message used to discover the engineID of SNMP agent.
If the Response message is correctly managed returning no error code, then 
the SNMPv3 protocol (already activated) is used to continue the 
communication between SNMP manager and agent.
Instead, if the Response message return an error code, the SNMP protocol 
has to switch to SNMPv2 in order to exchange the correct messages between 
SNMP manager and agent.

The Request discovery message is a SNMPv3 message with the following 
fields:
• A securityLevel of noAuthNoPriv
• A msgUserName of zerolength
• A msgAutoritativeID value of zerolength
• An empty variable-binding

In the Response message the local snmpEngineID value will be supplied 
within the msgAuthoritativeEngineID. The Report PDU will include the 
usmStatsUnknownEngineID counter in its variable-binding.

Since at the moment I cannot reach the author and other SNMP experts... 
can anyone please translate this for me in something comprehensible?! :-) 
So I could implement this behaviour... :-)

Thank you so much,

Ing. Marco Bresciani
Alcatel-Lucent 
Java Developer
WTD R&D Software Competence Center
via Trento, 30; 20059 Vimercate (Mi); Italy
EMail: Marco.Bresciani at alcatel-lucent.it
Phone: +39 039 686 5546
Fax: +39 039 686 5546