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Hopefully someone can help me, I've searched this site and none of the answers have proven successful.

I've spun up a CentOS VM and installed net-snmp & net-snmp-utils. I am trying to do a snmpget or snmpwalk request to a remote host, (specifically demo.snmplabs.com)

I can successfully query my localhost:

[root@localhost]#snmpwalk -v 1 -c public localhost .1
SNMPv2-MIB::sysDescr.0 = STRING: Linux localhost.localdomain 3.10.0-862.2.3.e17.x86_64 #1
SMP Wed May 9 18:05:47 UTC 2018 x86_64
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (120235) 0:20:02.35
SNMPv2-MIB::sysContact.0 = STRING: Root <root@localhost> (configure /etc/snmp/snmp.local.conf)
...........

However, when I try this same request to a remote host I get no responses back from that host and the request times out 

[root@localhost]#snmpwalk -v 1 -c public demo.snmplabs.com .1
Timeout: No Response from demo.snmplabs.com

When I add the debug option, I can see the packets going out but never receiving them in return.

I've already performed the following troubleshooting steps:

  • able to ping the remote host (demo.snmplabs.com)
  • verified the snmpd service is available and running
  • verified the snmp UDP port is open via netstat
  • disabled the firewall & iptables

Not too familiar with the snmpd.conf file so maybe that's where the problem lies...

Any help would be appreciated.

yaySecurity
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  • Check what SNMP version (1, 2c or 3) is used on the remote host. Before all use command `snmpget -v 1 -c public sysName`. – Mikhail Khirgiy May 18 '18 at 05:33
  • I've tried all three versions and yet they all fail..each time is a timeout error – yaySecurity May 18 '18 at 15:29
  • That is why the problem is on remote host. – Mikhail Khirgiy May 18 '18 at 15:31
  • this remote host is a publicly hosted snmp server for people to test their programs so it supports all three versions. It is hosted by sourceforge for their PySNMP module if you want to look it up. – yaySecurity May 18 '18 at 15:40
  • Yes. It works. `snmpget -v2c -c public demo.snmplabs.com sysName.0` has get `SNMPv2-MIB::sysName.0 = STRING: MBCG` – Mikhail Khirgiy May 18 '18 at 20:26
  • You are trying to query ".1" that is almost snmp MIB root. It is highly likely that this subtree is forbidden on remote server. Try to get smth more specific like sysLocation.0 or ifDescr.1 Also ".1" is not a leaf node in mib tree, what are you expecting to get from it? – Yuri Lachin Jun 04 '18 at 16:19

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