Reintroducing domain check up here.

nucypher/network/nodes.py

@@ -928,10 +928,17 @@ class Learner:
             self.log.info("Bad response from teacher {}: {} - {}".format(current_teacher, response, response.content))
             return
 
+
+        if not set(self.learning_domains).intersection(set(current_teacher.serving_domains)):
+            _domains = ",".join(current_teacher.serving_domains)
+            self.log.debug(
+                f"{current_teacher} is serving {_domains}, which we aren't learning.")
+            return  # This node is not serving any of our domains.
+
+
         #
         # Deserialize
         #
-
         try:
             signature, node_payload = signature_splitter(response.content, return_remainder=True)
         except BytestringSplittingError as e: