Clusters and SNMP

Clusters and SNMP

You can use SNMP to manage a cluster by configuring a cluster interface for SNMP administrative access. Using an SNMP manager you can get cluster configuration and status information and receive traps.

You configure SNMP for a cluster in the same way as configuring SNMP for a standalone FortiGate unit. SNMP configuration changes made to the cluster are shared by all cluster units.

Each cluster unit sends its own traps and SNMP manager systems can use SNMP get commands to query each cluster unit separately. To set SNMP get queries to each cluster unit you must create a special get command that includes the serial number of the cluster unit.

Alternatively you can use the HA reserved management interface feature to give each cluster unit a different management IP address. Then you can create an SNMP get command for each cluster unit that just includes the management IP address and does not have to include the serial number.

SNMP get command syntax for the primary unit

Normally, to get configuration and status information for a standalone FortiGate unit or for a primary unit, an SNMP manager would use an SNMP get commands to get the information in a MIB field. The SNMP get command syntax would be similar to the following:

snmpget -v2c -c <community_name> <address_ipv4> {<OID> | <MIB_field>}

where:

<community_name> is an SNMP community name added to the FortiGate configuration. You can add more than one community name to a FortiGate SNMP configuration. The most commonly used community name is public.

<address_ipv4> is the IP address of the FortiGate interface that the SNMP manager connects to.

{<OID> | <MIB_field>} is the object identifier (OID) for the MIB field or the MIB field name itself. The HA MIB fields and OIDs are listed below:

SNMP field names and OIDs

fgHaOverride                 .1.3.6.1.4.1.12356.101.13.1.4.0            Whether HA override is disabled or enabled for the cluster unit.

fgHaAutoSync               .1.3.6.1.4.1.12356.101.13.1.5.0            Whether automatic HA synchronization is disabled or enabled.

To get the HA priority for the primary unit

The following SNMP get command gets the HA priority for the primary unit. The community name is public. The IP address of the cluster interface configured for SNMP management access is 10.10.10.1. The HA priority MIB field is fgHaPriority and the OID for this MIB field is 1.3.6.1.4.1.12356.101.13.1.3.0 The first command uses the MIB field name and the second uses the OID:

snmpget -v2c -c public 10.10.10.1 fgHaPriority

snmpget -v2c -c public 10.10.10.1 1.3.6.1.4.1.12356.101.13.1.3.0

SNMP get command syntax for any cluster unit

To get configuration status information for a specific cluster unit (for the primary unit or for any subordinate unit), the SNMP manager must add the serial number of the cluster unit to the SNMP get command after the community name. The community name and the serial number are separated with a dash. The syntax for this SNMP get command would be:

snmpget -v2c -c <community_name>-<fgt_serial> <address_ipv4> {<OID> | <MIB_field>}

where:

<community_name> is an SNMP community name added to the FortiGate configuration. You can add more than one community name to a FortiGate SNMP configuration. All units in the cluster have the same community name. The most commonly used community name is public.

<fgt_serial> is the serial number of any cluster unit. For example, FGT4002803033172. You can specify the serial number of any cluster unit, including the primary unit, to get information for that unit.

<address_ipv4> is the IP address of the FortiGate interface that the SNMP manager connects to.

{<OID> | <MIB_field>} is the object identifier (OID) for the MIB field or the MIB field name itself.

If the serial number matches the serial number of a subordinate unit, the SNMP get request is sent over the HA heartbeat link to the subordinate unit. After processing the request, the subordinate unit sends the reply back over the HA heartbeat link back to the primary unit. The primary unit then forwards the response back to the SNMP manager.

If the serial number matches the serial number of the primary unit, the SNMP get request is processed by the primary unit. You can actually add a serial number to the community name of any SNMP get request. But normally you only need to do this for getting information from a subordinate unit.

To get the CPU usage for a subordinate unit

The following SNMP get command gets the CPU usage for a subordinate unit in a FortiGate-5001SX cluster. The subordinate unit has serial number FG50012205400050. The community name is public. The IP address of the FortiGate interface is 10.10.10.1. The HA status table MIB field is fgHaStatsCpuUsage and the OID for this MIB field is  .3.6.1.4.1.12356.101.13.2.1.1.3.1. The first command uses the MIB field name and the second uses the OID for this table:

snmpget -v2c -c public-FG50012205400050 10.10.10.1 fgHaStatsCpuUsage

snmpget -v2c -c public-FG50012205400050 10.10.10.1 1.3.6.1.4.1.12356.101.13.2.1.1.3.1

FortiGate SNMP recognizes the community name with syntax <community_name>-<fgt_serial>. When the primary unit receives an SNMP get request that includes the community name followed by serial number, the FGCP extracts the serial number from the request. Then the primary unit redirects the SNMP get request to the

cluster unit with that serial number. If the serial number matches the serial number of the primary unit, the SNMP get is processed by the primary unit.

Getting serial numbers of cluster units

The following SNMP get commands use the MIB field name fgHaStatsSerial.<index> to get the serial number of each cluster unit. Where <index> is the cluster unit’s cluster index and 1 is the cluster index of the primary unit, 2 is the cluster index of the first subordinate unit, and 3 is the cluster index of the second subordinate unit.

The OID for this MIB field is 1.3.6.1.4.1.12356.101.13.2.1.1.2.1. The community name is public. The IP address of the FortiGate interface is 10.10.10.1.

The first command uses the MIB field name and the second uses the OID for this table and gets the serial number of the primary unit:

snmpget -v2c -c public 10.10.10.1 fgHaStatsSerial.1

snmpget -v2c -c public 10.10.10.1 1.3.6.1.4.1.12356.101.13.2.1.1.2.1

The second command uses the MIB field name and the second uses the OID for this table and gets the serial number of the first subordinate unit:

snmpget -v2c -c public 10.10.10.1 fgHaStatsSerial.2

snmpget -v2c -c public 10.10.10.1 1.3.6.1.4.1.12356.101.13.2.2.2

SNMP get command syntax – reserved management interface enabled

To get configuration and status information for any cluster unit where you have enabled the HA reserved management interface feature and assigned IP addresses to the management interface of each cluster unit, an SNMP manager would use the following get command syntax:

snmpget -v2c -c <community_name> <mgmt_address_ipv4> {<OID> | <MIB_field>}

where:

<community_name> is an SNMP community name added to the FortiGate configuration. You can add more than one community names to a FortiGate SNMP configuration. The most commonly used community name is public.

<mgmt_address_ipv4> is the IP address of the FortiGate HA reserved management interface that the SNMP manager connects to.

{<OID> | <MIB_field>} is the object identifier (OID) for the MIB field or the MIB field name itself. To find OIDs and MIB field names see your FortiGate unit’s online help.