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    Net-SNMP Restarts Every Few Minutes

    Scheduled Pinned Locked Moved SNMP
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    • C
      cct-ckatri
      last edited by

      I'm having this really strange issue where Net-SNMP will restart every ~5 minutes, I do not see anything in the system logs about it exiting or the like, but if I monitor ps -o etime -p $(pgrep snmp) it restarts after ~5 minutes. I have 18 firewalls with SNMP and it happens consistently on like 3 of them.

      It doesn't happen all of the time, but usually overnight it will restart then get stuck in the restart loop for a while.

      pfSense 2.7.2
      pfsense-pkg-net-snmp 0.1.5_11
      net-snmp 5.9.1_4,1

      1 Reply Last reply Reply Quote 0
      • C
        cct-ckatri
        last edited by cct-ckatri

        It just started happening again after it being fine for a couple of hours, here is the syslog for the last couple of restarts

        Apr 9 20:28:56 	snmpd 	74272 	nlist err: neither tcb nor _tcb found.
Apr 9 20:28:56 	snmpd 	73937 	nlist err: neither tcb nor _tcb found.
Apr 9 20:28:56 	snmpd 	73937 	nlist err: neither udb nor _udb found.
Apr 9 20:28:56 	snmpd 	74272 	nlist err: neither udb nor _udb found.
Apr 9 20:28:56 	snmpd 	74272 	Turning on AgentX master support.
Apr 9 20:28:56 	snmpd 	73937 	Turning on AgentX master support.
Apr 9 20:28:56 	snmpd 	73937 	Error opening specified endpoint "udp:redacted:161"
Apr 9 20:28:56 	snmpd 	73937 	Server Exiting with code 1
Apr 9 20:28:56 	snmpd 	74595 	NET-SNMP version 5.9.1
Apr 9 20:35:04 	snmpd 	22851 	nlist err: neither tcb nor _tcb found.
Apr 9 20:35:04 	snmpd 	23114 	nlist err: neither tcb nor _tcb found.
Apr 9 20:35:04 	snmpd 	22851 	nlist err: neither udb nor _udb found.
Apr 9 20:35:04 	snmpd 	23114 	nlist err: neither udb nor _udb found.
Apr 9 20:35:04 	snmpd 	22851 	Turning on AgentX master support.
Apr 9 20:35:04 	snmpd 	23114 	Turning on AgentX master support.
Apr 9 20:35:04 	snmpd 	23114 	Error opening specified endpoint "udp:redacted:161"
Apr 9 20:35:04 	snmpd 	23114 	Server Exiting with code 1
Apr 9 20:35:04 	snmpd 	23294 	NET-SNMP version 5.9.1
Apr 9 20:41:07 	snmpd 	47662 	nlist err: neither tcb nor _tcb found.
Apr 9 20:41:07 	snmpd 	47762 	nlist err: neither tcb nor _tcb found.
Apr 9 20:41:07 	snmpd 	47662 	nlist err: neither udb nor _udb found.
Apr 9 20:41:07 	snmpd 	47762 	nlist err: neither udb nor _udb found.
Apr 9 20:41:07 	snmpd 	47662 	Turning on AgentX master support.
Apr 9 20:41:07 	snmpd 	47762 	Turning on AgentX master support.
Apr 9 20:41:07 	snmpd 	47762 	Error opening specified endpoint "udp:redacted:161"
Apr 9 20:41:07 	snmpd 	47762 	Server Exiting with code 1
Apr 9 20:41:07 	snmpd 	51150 	NET-SNMP version 5.9.1
        dennypageD 1 Reply Last reply Reply Quote 0
        • dennypageD
          dennypage @cct-ckatri
          last edited by

          @cct-ckatri do you have both net-snmp and bsnmp enabled?

          C 1 Reply Last reply Reply Quote 0
          • C
            cct-ckatri @dennypage
            last edited by cct-ckatri

            @dennypage yes, bsnmp is setup to bind only to localhost, net-snmp is set to bind only on WAN, then I have proxy -v2c -c public 127.0.0.1:161 .1.3.6.1.4.1.12325 added to the advanced options in the net-snmp config.

            I have this same exact setup on a bunch of pfSenses, but this issue only happens on like 3 of them.

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            • C
              cct-ckatri
              last edited by

              Any ideas on this? It makes monitoring very annoying since it cuts out so much.

              dennypageD 1 Reply Last reply Reply Quote 0
              • dennypageD
                dennypage @cct-ckatri
                last edited by

                @cct-ckatri This was one of those "If you don't have anything good to say, then don't say anything" situations.

                But since you asked, my recommendation is to disable one of the two conflicting SNMP implementations. I don't think it was ever intended that they both be active at the same time.

                And FWIW, in my opinion binding an SNMP implementation to the WAN interface on a firewall is a Bad Idea.

                Sorry.

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                • C
                  cct-ckatri
                  last edited by cct-ckatri

                  Thanks, hopefully it's not crashing due to a conflict, cause it'll make the whole proxy thing worthless since it's not possible to get the pf MIB data from net-snmp and bsnmp doesn't support SNMPv3.

                  My firewall rules are setup so that only my zabbix server is able to access the SNMP server, so that's why I'm not too stressed about it being on the WAN.

                  Maybe I could try running a zabbix proxy on the firewall itself and just having bsnmp bound to localhost... I might have to give that a shot.

                  dennypageD 1 Reply Last reply Reply Quote 0
                  • dennypageD
                    dennypage @cct-ckatri
                    last edited by

                    @cct-ckatri said in Net-SNMP Restarts Every Few Minutes:

                    it's not possible to get the pf MIB data from net-snmp and bsnmp doesn't support SNMPv3.

                    You could also extend net-snmp. It's likely that whatever data you are looking for is available via command line tools.

                    1 Reply Last reply Reply Quote 0
                    • C
                      cct-ckatri
                      last edited by

                      I figured it out 🤦. My firewalls had an old unused OpenVPN client connection on it that was unstable and every time it reconnected, it got a new IP address causing pfsense to restart all packages, and since it took down SNMP, we wouldn't get alerted about the interface going down either...
                      So this issue is solved now

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