diff --git a/tests/topotests/lib/lutil.py b/tests/topotests/lib/lutil.py
index 0b6a946fda..f8f580632e 100644
--- a/tests/topotests/lib/lutil.py
+++ b/tests/topotests/lib/lutil.py
@@ -25,6 +25,7 @@ import json
 import math
 import time
 from lib.topolog import logger
+from lib.topotest import json_cmp
 from mininet.net import Mininet
 
 
@@ -194,6 +195,10 @@ Total %-4d                                                           %-4d %d\n\
         global net
         if op != "wait":
             self.l_line += 1
+
+        if op == "jsoncmp_pass" or op == "jsoncmp_fail":
+            returnJson = True
+
         self.log(
             "%s (#%d) %s:%s COMMAND:%s:%s:%s:%s:%s:"
             % (
@@ -227,6 +232,33 @@ Total %-4d                                                           %-4d %d\n\
                     )
         self.log("COMMAND OUTPUT:%s:" % report)
 
+        # JSON comparison
+        if op == "jsoncmp_pass" or op == "jsoncmp_fail":
+            try:
+                expect = json.loads(regexp)
+            except:
+                expect = None
+                self.log(
+                    "WARNING: JSON load failed -- confirm regex input is in JSON format."
+                )
+            json_diff = json_cmp(js, expect)
+            if json_diff != None:
+                if op == "jsoncmp_fail":
+                    success = True
+                else:
+                    success = False
+                    self.log("JSON DIFF:%s:" % json_diff)
+                ret = success
+            else:
+                if op == "jsoncmp_fail":
+                    success = False
+                else:
+                    success = True
+            self.result(target, success, result)
+            if js != None:
+                return js
+            return ret
+
         # Experiment: can we achieve the same match behavior via DOTALL
         # without converting newlines to spaces?
         out_nl = out