How to enable SNMP on Juniper SRX firewalls

You can enable SNMP from the JunOS command line. You’ll need Telnet, SSH, or serial (console) access to the Juniper device.

1. Telnet, SSH, or serial (console) into your Juniper device.
2. Set the system community and authorization level: 

user@host# set snmp community community_string authorization read-only

• Note: Replace community_string with your desired community string

3. Authorize the network where the Auvik collector will be located to communicate with the SNMP agent: 

user@host# set snmp community community_string clients 192.168.1.0/32

• Note: Replace 192.168.1.0/32 with the Auvik collector network
• Note: Replace community_string with your desired community string

4. Commit the configuration: user@host# commit

5. If you use a community string other than public or private, add it to Auvik by following these steps.

Sources:  http://www.juniper.net/techpubs/en_US/junos15.1/topics/task/configuration/snmp-community-string-configuring-junos-nm.html