Limitations and Precautions for Port Pre-allocation and Incremental Allocation
Hardware Requirements
The Port Pre-allocation and Incremental Allocation function is supported by all models.
License Requirements
The Port Pre-allocation and Incremental Allocation function is not license-controlled.
Restrictions
To use port pre-allocation in hot standby networking in load balancing mode, run the nat resource load-balance enable command first.
In the load balancing networking, the address pool mode for port pre-allocation must be PAT mode.
In hot standby networking, when configuring port pre-allocation, ensure that the address pools on the active and standby devices are consistent. Otherwise, services may be abnormal.
In load-balancing hot standby networking, when port pre-allocation is used, the active device assigns the port resources with an even address pool ID, and the standby device assigns the port resources with an odd address pool ID. Address pool IDs need to be set on both active and standby devices and cannot be all odd numbers or even numbers. Otherwise, port resources that are not assigned by the local device need to be requested from the peer device through the heartbeat interfaces, which increases the burden on the heartbeat interfaces. For example, you are not advised to set the address pool IDs on the active and standby devices to an even number (2, 4, 6, or 8) or an odd number (1, 3, 5, or 7).
Functions such as excluding ports from an address pool, and configuring the working status for an address pool cannot be implemented together with port pre-allocation. After PAT is employed, do not configure incremental allocation. For details about how to configure port pre-allocation and incremental allocation, see Port Pre-allocation and Incremental Allocation.
IPv6 addresses cannot be configured in port pre-allocation because IPv6 address pools are not supported.