In your command line I don’t see the --master-addr option which is required for a multi-node training. Do you mind retrying your job with the following?
# Node 0
pytorch -m torch.distributed.launch --nnode=2 --node_rank=0 --nproc_per_node=1 --master_addr="<hostname_of_rank_0>" multi_gpu_practice/getting_start.py --local_world_size=1

# Node 1
pytorch -m torch.distributed.launch --nnode=2 --node_rank=1 --nproc_per_node=1 --master_addr="<hostname_of_rank_0>" multi_gpu_practice/getting_start.py --local_world_size=1