diff --git a/design_notes/KNOWN_BUGS b/design_notes/KNOWN_BUGS
index 72fe5e7..73c6a6b 100644
--- a/design_notes/KNOWN_BUGS
+++ b/design_notes/KNOWN_BUGS
@@ -2,3 +2,5 @@
   rendering as one node if they share the address. This is the case when a
   network split occurs and at least two routers in the same transit network get
   isolated.
+
+  We only support OSPFv3 at this time.