Don't try to use the incompatible pylibpcap library
diff --git a/src/python/oftest/dataplane.py b/src/python/oftest/dataplane.py
index 717a85f..76aff75 100644
--- a/src/python/oftest/dataplane.py
+++ b/src/python/oftest/dataplane.py
@@ -30,7 +30,9 @@
 have_pypcap = False
 try:
     import pcap
-    have_pypcap = True
+    if hasattr(pcap, "pcap"):
+        # the incompatible pylibpcap library masquerades as pcap
+        have_pypcap = True
 except:
     pass