I want to explore the SNMP binding. First i start with something very simple, grepping the the uptime of a host (IP.Adr.YY.AA) in my network. Leveraging ManageEngine MibBrowser Free Tool, this is working fine and I also see the Object ID being: .1.3.6.1.2.1.1.3
ManageEngine MibBrowser Free Tool reports back whatever days, hours, minutes and seconds the host is up. Also, the tool is in the same network as my OpenHAB 1.8.3 on raspberry.
My trouble is, OpenHAB seems to get no response. When i tcpdump i get the following which looks like openHAB/raspberry requesting it but no answer comes back:
udo tcpdump -v port 2025
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
19:43:19.990193 IP (tos 0x0, ttl 64, id 6368, offset 0, flags [DF], proto UDP (17), length 72)
IP.Adr.YY.ZZ.2025 > IP.Adr.YY.AA.snmp: { SNMPv1 C=homesnmp { GetRequest(27) R=702051329 system.sysUpTime } }
19:44:20.001266 IP (tos 0x0, ttl 64, id 8833, offset 0, flags [DF], proto UDP (17), length 72)
IP.1Adr.YY.ZZ.2025 > IP.Adr.YY.AA.snmp: { SNMPv1 C=homesnmp { GetRequest(27) R=702051330 system.sysUpTime } }
19:45:20.012656 IP (tos 0x0, ttl 64, id 10202, offset 0, flags [DF], proto UDP (17), length 72)
IP.Adr.YY.ZZ.2025 > IP.Adr.YY.AA.snmp: { SNMPv1 C=homesnmp { GetRequest(27) R=702051331 system.sysUpTime } }
I would guess, it has to do with the way its being setup (snmp / snmpd / snmptrapd). I leveraged the configuration as described in the SNMP Binding doc. Including the details about binding port for *nix as I am leveraging Raspberry.
cat /etc/snmp/snmptrapd.conf
authCommunity log,execute,net MYSNMPCommunity
disableAuthorization yes
forward default udp:IP.Adr.YY.ZZ:2025
cat /etc/snmp/snmpd.conf
agentAddress udp:161
cat /opt/openhab/configurations/openhab.cfg |grep snmp
snmp:port=2025
snmp:community=MYSNMPCommunity
#snmp:timeout=
#snmp:retries=
Anyone an idea, why my openHAB 1.8.3 does not get any information? To me it seems something is wrong with the config. By teh way, netstat -lnp discloses the following:
udp 0 0 0.0.0.0:161 0.0.0.0:* 831/snmpd
udp 0 0 0.0.0.0:49840 0.0.0.0:* 831/snmpd
udp6 0 0 :::2025 :::* 1155/java
This seems to tell me, openHAB is listening on IPv6 instead of udp IPv4. Could that be the reason and if yes, how do i change this?