diff --git a/python/tools/benchmark.py b/python/tools/benchmark.py
index 36c5e74a0b85e92011235c839aa486a691d63394..32e8bf60369a94b7f1ee2f439353c9d0dd025433 100755
--- a/python/tools/benchmark.py
+++ b/python/tools/benchmark.py
@@ -186,6 +186,7 @@ if __name__ == '__main__':
     wb = WorkBench(args.ifname, args.virtual_locs, args.node_num, loss=args.loss,
             delay=args.delay, disable_ipv4=args.disable_ipv4,
             disable_ipv6=args.disable_ipv6)
+    wb.create_virtual_net()
     bootstrap = wb.get_bootstrap()
 
     bs_dht_log_enabled = False
@@ -203,7 +204,6 @@ if __name__ == '__main__':
         bs_dht_log_enabled = True
         bootstrap.front().enableLogging()
 
-    wb.create_virtual_net()
     bootstrap.resize(1)
     print("Launching", wb.node_num, "nodes (", wb.clusters, "clusters of", wb.node_per_loc, "nodes)")
 
diff --git a/python/tools/dht/tests.py b/python/tools/dht/tests.py
index b53f34dc07b41329ade410961d85c1effb5ba4c7..40d86da3881e2eea2742729c0d018a284e6b77c7 100644
--- a/python/tools/dht/tests.py
+++ b/python/tools/dht/tests.py
@@ -11,6 +11,7 @@ import string
 import time
 import subprocess
 import re
+import traceback
 import collections
 
 from matplotlib.ticker import FuncFormatter