diff --git a/dags/test-train-pytorch.py b/dags/test-train-pytorch.py
index 853bd55..8393b4a 100644
--- a/dags/test-train-pytorch.py
+++ b/dags/test-train-pytorch.py
@@ -40,17 +40,13 @@ def run_training_node_func(rank, world_size):
   import time
 
   # CRITICAL: Set NCCL environment variables BEFORE importing torch
-  # This ensures NCCL reads these settings during initialization
+  # NOTE: IB is disabled due to subnet manager PKEY mismatch (test-2 only has limited membership 0x7fff)
+  # Cluster admin needs to configure opensm partitions to assign full membership PKEYs to both ports
   os.environ['NCCL_DEBUG'] = 'INFO'
   os.environ['NCCL_TIMEOUT'] = str(NCCL_TIMEOUT)
   os.environ['TORCH_NCCL_BLOCKING_WAIT'] = '1'  # Updated naming
-  os.environ['NCCL_IB_DISABLE'] = '0'  # Enable IB
-  os.environ['NCCL_SOCKET_IFNAME'] = 'eth0'  # Fallback to eth0
-  os.environ['NCCL_IB_GID_INDEX'] = '3'  # Use RoCE v2 (GID index 3)
-  os.environ['NCCL_IB_TC'] = '106'  # Traffic class for RoCE
-  os.environ['NCCL_IB_TIMEOUT'] = '22'  # IB timeout (higher = more tolerant)
-  os.environ['NCCL_IB_RETRY_CNT'] = '7'  # IB retry count
-  os.environ['NCCL_NET_GDR_LEVEL'] = '5'  # Enable GPUDirect RDMA
+  os.environ['NCCL_IB_DISABLE'] = '1'  # Disable IB - use ethernet (PKEY misconfiguration)
+  os.environ['NCCL_SOCKET_IFNAME'] = 'eth0'  # Use ethernet (working)
   os.environ['NCCL_P2P_DISABLE'] = '0'  # Enable P2P
   os.environ['NCCL_IGNORE_CPU_AFFINITY'] = '1'  # Better compatibility
 
@@ -137,9 +133,8 @@ def run_training_node_func(rank, world_size):
   print(f"  MASTER_PORT: {MASTER_PORT}")
   print(f"  RANK: {rank}")
   print(f"  WORLD_SIZE: {world_size}")
-  print(f"  NCCL_IB_DISABLE: {os.environ.get('NCCL_IB_DISABLE')} (IB enabled)")
-  print(f"  NCCL_IB_GID_INDEX: {os.environ.get('NCCL_IB_GID_INDEX')}")
-  print(f"  NCCL_IB_TIMEOUT: {os.environ.get('NCCL_IB_TIMEOUT')}")
+  print(f"  NCCL_IB_DISABLE: {os.environ.get('NCCL_IB_DISABLE')} (ethernet mode)")
+  print(f"  NCCL_SOCKET_IFNAME: {os.environ.get('NCCL_SOCKET_IFNAME')}")
 
   # STEP 3.5: Pre-flight checks
   print(f"[{rank}] Running pre-flight checks...")