This article describes the troubleshooting procedure for device discovery via SNMP probe.

Trying to discover the device using SNMP as probe, probe fails with following error:

Junos Space is unable to query the device information through SNMP. Check the SNMP settings on the device to verify SNMP is not blocked and the SNMP settings specified in Junos Space match the device SNMP settings.

Junos Space normally polls the device in order to discover it. This can be caused by an incorrect SNMP configuration on the device or network.

To discover the device using the Junos Space WebUI, please refer to Discovering Devices

To discover the device, follow these instructions:

• To discover the device using SNMP, you must have the following configuration on the device: (community public is used as an example only):

  # show snmp
  community public {
                    authorization read-only;
    }

• You can configure it using the following CLI:

  # set snmp community public authorization read-only

  Note: In the above command, replace community string with your community string.

  If you have a list of clients defined, then configure eth0 IP of Space on the device to allow access:

  # set snmp community public clients 1.1.1.1

  Where 1.1.1.1 is the Space server's device management IP.

  Note: Junos Space uses its device management IP (eth0 or eth3) to poll the device. Make sure that IP is allowed to poll the device.

  For J-series and SRX-series, JunOS version 8.5 or above:

  You must allow SNMP in the zone where the management interface is configured.

    # show security zones security-zone mgmt host-inbound-traffic
system-services {
                snmp;
                }
   

  If it is not configured, then run the following command in Edit mode:

  # set security zones security-zone mgmt host-inbound-traffic system-services snmp

• If SNMP V3 is configured on the device, verify the config as per the following:

  • Example: SNMPv3 Configuration
  • KB22048 - Example: How to configure SNMPv3 [juniper.net]

• Verify that you are able to poll the device via Junos Space CLI. You can do so by using the following command:

  • For SNMP V2, the snmpwalk command will be:

    • snmpwalk -v2c -c <community-string> <target-device-ip>

    • e.g.:  snmpwalk -v2c -c public 2.2.2.2

      If this fails with a timeout error:

      Timeout: No Response from 2.2.2.2

    • It indicates an issue in polling the device. Successful execution will display a list of OID

  • For SNMP V3, the snmpwalk command will be:

    • snmpwalk -v3 -l authPriv -u <UserID> -a <Authentication_Type>   -A <"Authentication_Key">  -x <Privacy_Type>   -X  <"Privacy_Key">  <target-device-ip>
      
      Example:

      snmpwalk -v3 -l authPriv -u Space -a MD5  -A juniper1  -x AES  -X  juniper1  3.3.3.3
      
      

• If you have the interface in a routing instance on a device, please refer to KB13080 - How to permit SNMP polling for an interface in a routing instance [juniper.net] .

• Make sure all necessary ports are open in the network to allow management of the device.  KB18148 - What network ports need to be opened for Junos Space [juniper.net]

If you are still not able to discover the device, contact your technical support representative for further troubleshooting.
 

2019-06-15: Added SNMPV3 snmpwalk command to check and change the link for the tech doc and how to configure SNMPv3 on JunOS devices.
2019-11-04: Corrected snmpwalk v2 example by adding space between "-c" and community string
2024-05-17: Link corrected