--- old/vtysh/vtysh_user.c.orig	2006-11-03 01:53:58.000000000 +0100
+++ new/vtysh/vtysh_user.c	2006-11-03 01:59:02.000000000 +0100
@@ -60,2 +60,4 @@ vtysh_pam (const char *user)
     ret = pam_authenticate (pamh, 0);
+  if (ret != PAM_SUCCESS)
+    printf("Not authenticated. Check /etc/pam.d/quagga.\n");
   /* printf ("ret %d\n", ret); */