Index: traceroute.h
===================================================================
--- traceroute.h	(revision 14654)
+++ traceroute.h	(working copy)
@@ -111,6 +111,10 @@
 #define G_TTL(x) (x == G_ALIVE_TTL || x == G_DEAD_TTL)
 
 #define MAX_TTL 50
+/* If the distance to the target is not known (it's not responsive to the probe
+   we're using), the maximum number of consecutive timeouts we'll tolerate
+   before giving up. */
+#define UNKNOWN_DIST_MAX_TIMEOUTS 3
 
 #define HOP_COL 0
 #define RTT_COL 1
Index: traceroute.cc
===================================================================
--- traceroute.cc	(revision 14654)
+++ traceroute.cc	(working copy)
@@ -1146,8 +1146,15 @@
                 noDistProbe = true;
                 if (o.verbose)
                     log_write (LOG_STDOUT, "%s: no reply to our hop distance probe!\n", IPStr ());
-            } else if (it->second->ttl > MAX_TTL) {
-                setState(G_DEAD_TTL);
+            } else {
+                /* We are done if
+                   1. We don't know the distance to the host and have gotten a
+                      number of consecutive timeouts, or
+                   2. We've reached the maximum TTL limit. */
+                if (noDistProbe && consecTimeouts >= UNKNOWN_DIST_MAX_TIMEOUTS)
+                    setState(G_FINISH);
+                else if (it->second->ttl > MAX_TTL)
+                    setState(G_DEAD_TTL);
             }
         } else {
             droppedPackets++;