Commit 100% working part of patch from Laurent Rabret ([quagga-dev 830]).
Also tiny temporary fix from me to spf thread crash. Will look at it later.
diff --git a/isisd/isis_constants.h b/isisd/isis_constants.h
index 852b8a1..c732bfc 100644
--- a/isisd/isis_constants.h
+++ b/isisd/isis_constants.h
@@ -65,7 +65,7 @@
 #define ISIS_LEVEL1                   1
 #define ISIS_LEVEL2                   2
 
-#define HELLO_INTERVAL                1
+#define HELLO_INTERVAL                10
 #define HELLO_MINIMAL HELLO_INTERVAL
 #define HELLO_MULTIPLIER              3
 #define DEFAULT_PRIORITY              64