3 Replies Latest reply on Aug 30, 2010 8:54 AM by nbm2

    SNMP not responding

      I have installed Net-SNMP on Linux machine.

      It is binded to port udp 161

      I start it with the command: snmpd -Lo

      when I do 

           snmpget -v 1 -c public localhost system.sysObjectID.0

      on the same machine the snmpd is running on- I get a respond

          SNMPv2-MIB::sysObjectID.0 = OID: ccitt.1

      when I send same request from another (Windows) machine (using SNMPc program) - I see no reaction.

      I used "wireshark" to monitor packets, and I see the requests sent from the other machine. I also see them get to the first machine.

      Do you have an idea why isn't it working?

        • Re: SNMP not responding
          Questionario

          did you allow the orion server to access the remote server via SNMP?

          in windows you can do that in the settings of the SNMP service.

          not sure how to do that in linux or if it is required to specify remote servers allowed to access SNMP (I would guess so though!)

          • Re: SNMP not responding
            cgregors

            On most stock Linux installations, the firewall is enabled by default. Depending on your distribution, you will need to either open port 161/udp for snmp or disable the firewall.

            <c>

            • Re: SNMP not responding

              1.   Not sure how to check settings of the SNMP service (whether it is allowing access to the remote server)...

              2.   I checked again, and no firewall is enabled

              3.   when using "iptables" command I see no rules at all (empty table), which means, as far as I understand, that no filter is performed. which is good... :-)

              4. I ran snmpd with -f -Lo -d flags to debug packet traffic and I have noticed that except from request-ID, there is no differance between the 2 requests the snmpd gets - and still, it only answer the local one:

               

              Received 42 bytes from UDP: [172.26.9.5]:58633->[172.26.20.200]

              0000: 30 28 02 01  00 04 06 70  75 62 6C 69  63 A0 1B 02    0(.....public...

              0016: 03 00 DD 54  02 01 00 02  01 00 30 0E  30 0C 06 08    ...T......0.0...

              0032: 2B 06 01 02  01 01 02 00  05 00                       +.........

               

              Received SNMP packet(s) from UDP: [172.26.9.5]:58633->[172.26.20.200]

                GET message

                  -- SNMPv2-MIB::sysObjectID.0

               

               

              Received 43 bytes from UDP: [127.0.0.1]:46183->[127.0.0.1]

              0000: 30 29 02 01  00 04 06 70  75 62 6C 69  63 A0 1C 02    0).....public...

              0016: 04 16 CC AA  2E 02 01 00  02 01 00 30  0E 30 0C 06    ...........0.0..

              0032: 08 2B 06 01  02 01 01 02  00 05 00                    .+.........

               

              Received SNMP packet(s) from UDP: [127.0.0.1]:46183->[127.0.0.1]

                GET message

                  -- SNMPv2-MIB::sysObjectID.0

               

              Sending 44 bytes to UDP: [127.0.0.1]:46183->[127.0.0.1]

              0000: 30 2A 02 01  00 04 06 70  75 62 6C 69  63 A2 1D 02    0*.....public...

              0016: 04 16 CC AA  2E 02 01 00  02 01 00 30  0F 30 0D 06    ...........0.0..

              0032: 08 2B 06 01  02 01 01 02  00 06 01 01                 .+..........