[SNMP4J] Agent / manager reconnect problem

[Railsback, Jonathan]

I have an SNMP manager that I wrote using SNMP4j, as well as a series of agents that I wrote using SNMP4j-Agent.

I am having a problem where I intermittently get the message <> after one of my agents restarts.

Here is a sample of the snmp agent's log after it has been stopped then restarted, showing the manager unable to get a response:

51643 [DefaultUDPTransportMapping_192.168.41.133/9012] WARN org.snmp4j.MessageDispatcherImpl  - 1.3.6.1.6.3.15.1.1.2.0 = 3
54644 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.transport.DefaultUdpTransportMapping  - Received message from /192.168.41.123/38251 with length 308: 30:82:01:30:02:01:03:30:11:02:04:73:9a:c1:75:02:03:00:ff:ff:04:01:07:02:01:03:04:35:30:33:04:06:c0:a8:29:65:5a:2a:02:01:01:02:02:00:ee:04:0a:61:67:65:6e:74:2d:75:73:65:72:04:0c:e9:7b:a3:5e:6d:1b:0b:30:bd:32:3c:29:04:08:00:00:00:01:dc:cb:d6:dc:04:81:e0:1a:09:05:4f:56:01:01:07:8c:7f:c5:62:1a:92:ad:31:14:d0:8d:ba:be:b5:6c:19:55:1a:9a:fa:18:34:2a:5a:5d:8d:69:aa:87:9b:87:7b:ff:96:98:b3:64:df:fc:81:e7:88:b0:72:1e:39:04:b1:38:51:54:00:40:96:b6:a6:8c:17:c3:c4:5d:fa:e6:aa:6c:6b:c9:43:bc:5e:b9:d6:ce:29:08:7d:16:ae:22:9c:33:1c:88:08:dd:5d:4e:10:6f:3f:21:a5:3a:ae:d3:fc:ac:ec:ed:6d:e2:f8:94:ee:de:ec:ae:08:b1:37:db:ba:99:27:3f:09:b2:bc:d9:73:7a:70:a4:9f:9f:0f:c4:28:a3:a8:d7:b4:7c:11:08:13:02:7c:be:4b:2f:83:f0:2a:76:3a:0a:89:1b:52:9e:ea:d5:c5:66:44:d6:5f:6e:04:85:70:e9:b5:e6:71:f8:ce:59:5b:7d:e2:64:fb:c3:f8:40:1e:7a:2a:c3:c9:eb:91:0f:e8:05:05:d5:bd:9d:32:39:90:1d:8e:0a:fd:bd:22:57:50:ed:03:43:67:81:05:2d:30:52:12:4f:e4:e5:2b
54644 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.mp.MPv3  - SNMPv3 header decoded: msgId=1939521909, msgMaxSize=65535, msgFlags=07, secModel=3
54644 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.security.USM  - getUser(engineID=c0:a8:29:65:5a:2a, securityName=agent-user)
54644 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.security.UsmTimeTable  - CheckTime: received message outside time window (authorative):183 > 150
54644 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.security.USM  - RFC3414 §3.2.7.a Not in time window; engineID='c0:a8:29:65:5a:2a', engineBoots=1, engineTime=238
54645 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.mp.MPv3  - Adding cache entry: StateReference[msgID=1939521909,pduHandle=PduHandle[815628490],securityEngineID=c0:a8:29:65:5a:2a,securityModel=org.snmp4j.security.USM at 10ffb38,securityName=agent-user,securityLevel=3,contextEngineID=,contextName=]
54645 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.mp.MPv3  - Removed cache entry: StateReference[msgID=1939521909,pduHandle=PduHandle[815628490],securityEngineID=c0:a8:29:65:5a:2a,securityModel=org.snmp4j.security.USM at 10ffb38,securityName=agent-user,securityLevel=3,contextEngineID=,contextName=]
54645 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.security.USM  - RFC3414 §3.1.4.b Outgoing message is not encrypted
54645 [DefaultUDPTransportMapping_192.168.41.133/9012] DEBUG org.snmp4j.transport.DefaultUdpTransportMapping  - Sending message to 192.168.41.123/38251 with length 106: 30:68:02:01:03:30:11:02:04:73:9a:c1:75:02:03:00:ff:ff:04:01:01:02:01:03:04:2c:30:2a:04:06:c0:a8:29:65:5a:2a:02:01:01:02:01:36:04:0a:61:67:65:6e:74:2d:75:73:65:72:04:0c:ad:fc:78:bc:be:1a:42:1a:3c:9a:03:3e:04:00:30:22:04:00:04:00:a8:1c:02:01:00:02:01:00:02:01:00:30:11:30:0f:06:0a:2b:06:01:06:03:0f:01:01:02:00:41:01:04

What is very confusing is that all the initial connections work correctly, every time.  It just seems to be reconnects that have intermittent issues.  Sometimes reconnects work, sometimes they dont.

Any help, tips, or other insight would be greatly appreciated!

Thanks,

Jon