HCCL_IF_BASE_PORT
Description
Specifies the start port number of the host NIC in single-operator mode when the host NIC is used for HCCL initialization or collective communication. When the variable is configured, the system occupies 16 ports starting from the specified port by default.
The value of this environment variable must be an integer ranging from 1024 to 65520. Ensure that the allocated port is not occupied.
Example
export HCCL_IF_BASE_PORT=50000
Restrictions
In distributed training scenarios, HCCL uses certain ports of the host server to collect cluster information, requiring the operating system to reserve these ports.
- If you do not specify a port using the HCCL_IF_BASE_PORT environment variable, HCCL uses ports 60000 to 60015 by default. You need to run the following command to reserve OS ports in this range:
sysctl -w net.ipv4.ip_local_reserved_ports=60000-60015
- If you use the HCCL_IF_BASE_PORT environment variable to specify a port, for example, 50000, HCCL uses ports 50000 to 50015. You need to run the following command to reserve OS ports in this range:
sysctl -w net.ipv4.ip_local_reserved_ports=50000-50015
Applicability
Parent topic: Collective Communication