Version:

Version:

Version:

Version:

Version:


Table of Contents

FortiGate-7000E Handbook

Controlling SNAT port partitioning behavior

You can use the following command to control how the FortiGate-7000E partitions source NAT (SNAT) source ports among FPMs:

config load-balance setting

set nat-source-port {chassis-slots | enabled-slots}

end

chassis-slots this option statically allocates SNAT source ports to all FPMs. The source port distribution is not affected by whether or not an FPM goes down, is disabled, or is taken offline for maintenance or some other purpose.

If an FPM goes down, is disabled, or is taken offline, the SNAT source ports assigned to that FPM will not be re-allocated to the FPMs that are still operating. Fewer source ports will be available, but all FPMs that are still operating will maintain the same SNAT source port allocation and active sessions being processed by the still operating FPMs will not be affected.

enabled-slots SNAT source port partitioning dynamically distributes SNAT source ports to operating FPMs. This is the default behavior and is recommended in most cases.

If an FPM goes down, is disabled, or is taken offline for maintenance or some other purpose, SLBC dynamically re-allocates SNAT source ports among the remaining FPMs. This means that all configured SNAT source ports remain available. If SNAT source ports are re-allocated when the FortiGate-7000E is actively processing traffic, some active sessions may be lost if their source ports are allocated to different FPMs.

Controlling SNAT port partitioning behavior

You can use the following command to control how the FortiGate-7000E partitions source NAT (SNAT) source ports among FPMs:

config load-balance setting

set nat-source-port {chassis-slots | enabled-slots}

end

chassis-slots this option statically allocates SNAT source ports to all FPMs. The source port distribution is not affected by whether or not an FPM goes down, is disabled, or is taken offline for maintenance or some other purpose.

If an FPM goes down, is disabled, or is taken offline, the SNAT source ports assigned to that FPM will not be re-allocated to the FPMs that are still operating. Fewer source ports will be available, but all FPMs that are still operating will maintain the same SNAT source port allocation and active sessions being processed by the still operating FPMs will not be affected.

enabled-slots SNAT source port partitioning dynamically distributes SNAT source ports to operating FPMs. This is the default behavior and is recommended in most cases.

If an FPM goes down, is disabled, or is taken offline for maintenance or some other purpose, SLBC dynamically re-allocates SNAT source ports among the remaining FPMs. This means that all configured SNAT source ports remain available. If SNAT source ports are re-allocated when the FortiGate-7000E is actively processing traffic, some active sessions may be lost if their source ports are allocated to different FPMs.