IBDP: detect oscillation in OSPF (#6823)

batfish · Apr 1, 2021 · fd170a7 · fd170a7
1 parent 6d367c2
commit fd170a7
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/projects/batfish/src/main/java/org/batfish/dataplane/ibdp/IncrementalBdpEngine.java b/projects/batfish/src/main/java/org/batfish/dataplane/ibdp/IncrementalBdpEngine.java
@@ -825,6 +825,8 @@ static SortedMap<String, SortedMap<String, Set<AbstractRoute>>> getRoutes(
                 vrfEntry -> ImmutableSet.copyOf(vrfEntry.getValue().getRoutes())));
   }
 
+  private static final int MAX_OSPF_INTERNAL_ITERATIONS = 100000;
+
   /**
    * Run the IGP OSPF computation until convergence.
    *
@@ -868,6 +870,10 @@ private int initOspfInternalRoutes(Map<String, Node> allNodes, OspfTopology ospf
                 .flatMap(n -> n.getVirtualRouters().stream())
                 .flatMap(vr -> vr.getOspfProcesses().values().stream())
                 .anyMatch(OspfRoutingProcess::isDirty);
+        if (ospfInternalIterations > MAX_OSPF_INTERNAL_ITERATIONS) {
+          throw new BdpOscillationException(
+              "OSPF did not converge after " + MAX_OSPF_INTERNAL_ITERATIONS + " iterations");
+        }
       } finally {
         span.finish();
       }