Securing SNMP (Linux / Windows)

SNMP is used for remote monitoring and configuration of dedicated servers. If you have not changed the default community string of public or privateYour server may be abused to conduct DDOS attacks. In addition, publicly accessible SNMP Information can leak about your server. We suggest using hard-to-guess community strings.

Windows machines

On Windows machines, SNMP is run through the SNMP service. To change the community string:

1. Open Control Panel -> Administrative Tools -> Services

2. Find SNMP Service right-click it, and choose Properties

3. On the Security tab, click the Add button near Accepted community names

4. Enter a secure password for this (do not reuse any existing password)

5. Make sure to remove any insecure passwords (default values such as public or private are commonly abused)

6. Click OK

7. Restart the SNMP service

Linux machines

On Linux machines, SNMP is commonly run through the net-snmp library:

1. Open your snmpd.conf file (usually /etc/snmp/snmpd.conf)

2. Find the line that looks like: com2sec notConfigUser default public (The line will begin with com2sec and end with a password. In this example, the password is public.

3. Change the public at the end of the line to a more secure password

4. Restart the SNMP server with: service snmpd restart