Version: NCCL version 2.5.6+cuda10.1 I have two machines, and each has two network interfaces and four GPUs. I configured the variable: NCCL_SOCKET_IFNAME=enP1p1s0f0,enP1p1s0f1 NCCL_DEBUG=INFO NCCL_SOCKET_NTHREADS=2 NCCL_NSOCKS_PERTHREAD=2But from the log, NCCL use only one interface...