Configuring SNMP Community Strings

SNMP community strings determine the access privileges (read-only and read-write) of SNMP clients with the device's SNMP agent. You can configure up to five read-only SNMP community strings and up to five read-write SNMP community strings. The device's SNMP agent accepts SNMP Get (read-only) and Set (read-write) requests only if the correct community string is used in the request.

You can also configure a unique password-like community string used for sending SNMP traps. The device sends the traps with the community string.

SNMP community strings are applicable only to SNMPv1 and SNMPv2c. SNMPv3 uses username-password authentication along with an encryption key (see Configuring SNMP V3 Users).
If you configure SNMPv3 users (see Configuring SNMPv3 Users), the device ignores all SNMP requests (Get and Set operations) from SNMPv2 users (sends the authenticationFailure trap).
The read-only community strings must be different to the read-write community strings.
You can enhance security by configuring Trusted Managers (see Configuring SNMP Trusted Managers). A Trusted Manager is an IP address from which the SNMP agent accepts Get and Set requests.

For detailed descriptions of the SNMP parameters, see SNMP Parameters

To configure SNMP community strings:
1. Open the SNMP Community Settings page (Setup menu > Administration tab > SNMP folder > SNMP Community Settings).
2. Under the Read-Only Community Strings group, in the 'Read-Only' fields, configure read-only community strings:

3. Under the Read-Write Community Strings group, in the 'Read-Write' fields, configure read-write community strings:

4. Under the Misc. Settings group, in the 'Trap Community String' field, configure a community string for SNMP traps:

5. Click Apply, and then restart the device with a save-to-flash for your settings to take effect.

You can hide (default) and show entered community strings, by toggling the hide and show buttons provided by each field.

To delete a community string, delete the configured string, click Apply, and then restart the device with a save-to-flash for your settings to take effect.

SNMP Community String Parameter Descriptions

Parameter

Description

'Read-Only'

configure system > snmp settings > ro-community-string

[SNMPReadOnlyCommunityStringsPassword_x]

Defines read-only SNMP community strings. Up to five read-only community strings can be configured.

The valid value is a string of up to 30 characters that can include only the following:

Upper- and lower-case letters (a to z, and A to Z)
Numbers (0 to 9)
Hyphen (-)
Underline (_)

For example, "Public-comm_string1".

The default is "public".

Note:

The password can't be configured with wide characters.
The password can't contain spaces.
To enforce the use of strong passwords (password complexity), configure the [EnforcePasswordComplexity] parameter to [1].
The read-only community strings must be different to the read-write community strings.
For ini file configuration, x is 0 for the 'Read-Only 1' parameter.

'Read-Write'

configure system > snmp settings > rw-community-string

[SNMPReadWriteCommunityStringsPassword_x]

Defines read-write SNMP community strings. Up to five read-write community strings can be configured.

The valid value is a string of up to 30 characters that can include only the following:

Upper- and lower-case letters (a to z, and A to Z)
Numbers (0 to 9)
Hyphen (-)
Underline (_)

For example, "Private-comm_string1".

The default is "private".

Note:

The parameter can't contain wide characters.
The password can't contain spaces.
To enforce the use of strong passwords (password complexity), configure the [EnforcePasswordComplexity] parameter to [1].
The read-write community strings must be different to the read-only community strings.
For ini file configuration, x is 0 for the 'Read-Write 1' parameter.

'Trap Community String'

configure system > snmp trap > community-string

[SNMPTrapCommunityStringPassword]

Defines the community string for SNMP traps.

The valid value is a string of up to 30 characters that can include only the following:

Upper- and lower-case letters (a to z, and A to Z)
Numbers (0 to 9)
Hyphen (-)
Underline (_)

For example, "Trap-comm_string1".

The default is "trapuser".

Note: The parameter cannot be configured with wide characters.