SNMPv3 not in time window

Question

I try to query a Cisco SMB (small business switch) to read its hostname.

My code returns "not in time window (1.3.6.1.6.3.15.1.1.2.0).

Net-Snmp works fine. The difference I found using wireshark is that net-snmp sets msgAuthorativeEngineTime after it receives not in time window error.

Discovery discovery = Messenger.GetNextDiscovery(SnmpType.GetRequestPdu);
ReportMessage report = discovery.GetResponse(60000, new IPEndPoint(IPAddress.Parse("10.105.9.10"), 161));

OctetString username = new OctetString("test");
var auth = new SHA1AuthenticationProvider(new OctetString("Testtest123!"));
var priv = new DESPrivacyProvider(new OctetString("Testtest123!"), auth);

// read switch hostname
GetRequestMessage request = new GetRequestMessage(VersionCode.V3, Messenger.NextMessageId, Messenger.NextRequestId, username, new List<Variable> { new Variable(new ObjectIdentifier("1.3.6.1.2.1.1.5.0")) }, priv, Messenger.MaxMessageSize, report);
ISnmpMessage reply = request.GetResponse(60000, router); (not in time window)

Please find a wireshark screenshot of sharp-snmp:

And net-snmp:

Thank you for your help!

Answer 1

According to the snmpget sample (updated link here), you have to call two times the GetRequestMessage method. Be aware that the code uses the report variable in the first call, then the reply one in the latter, otherwise it will not work (= not in time window message) (I lost half a day to get this!)