Reduce the hello interval.

babel.c

@@ -258,18 +258,18 @@ main(int argc, char **argv)
     }
 
     if(wireless_hello_interval <= 0)
-        wireless_hello_interval = 6000;
+        wireless_hello_interval = 4000;
     wireless_hello_interval = MAX(wireless_hello_interval, 5);
 
     if(wired_hello_interval <= 0)
-        wired_hello_interval = 30000;
+        wired_hello_interval = 20000;
     wired_hello_interval = MAX(wired_hello_interval, 5);
 
     if(update_interval <= 0)
         update_interval =
             MIN(MAX(wireless_hello_interval * 5, wired_hello_interval),
                 70000);
-    update_interval = MAX(update_interval, 20);
+    update_interval = MAX(update_interval, 70);
 
     if(seqno_interval <= 0)
         /* This should be slightly less than the self_update_interval */