Added ping_check and ssh_check functions and use it in exercise.sh

Change-Id: I69d41c9db527f60f250b6af36b2d8e9d0dd39684
diff --git a/stackrc b/stackrc
index f9a41bd..e587efa 100644
--- a/stackrc
+++ b/stackrc
@@ -136,10 +136,10 @@
 #IMAGE_URLS="http://launchpad.net/cirros/trunk/0.3.0/+download/cirros-0.3.0-x86_64-disk.img" # cirros full disk image
 
 # Set default image based on ``VIRT_DRIVER`` and ``LIBVIRT_TYPE``, either of
-# which may be set in ``localrc``.  Also allow ``DEFAULT_IMAGE_NAME`` and 
+# which may be set in ``localrc``.  Also allow ``DEFAULT_IMAGE_NAME`` and
 # ``IMAGE_URLS`` to be set directly in ``localrc``.
 case "$VIRT_DRIVER" in
-    openvz) 
+    openvz)
         DEFAULT_IMAGE_NAME=${DEFAULT_IMAGE_NAME:-ubuntu-11.10-x86_64}
         IMAGE_URLS=${IMAGE_URLS:-"http://download.openvz.org/template/precreated/ubuntu-11.10-x86_64.tar.gz"};;
     libvirt)
@@ -159,3 +159,6 @@
 
 # 5Gb default volume backing file size
 VOLUME_BACKING_FILE_SIZE=${VOLUME_BACKING_FILE_SIZE:-5130M}
+
+PRIVATE_NETWORK_NAME=${PRIVATE_NETWORK_NAME:-"private"}
+PUBLIC_NETWORK_NAME=${PUBLIC_NETWORK_NAME:-"nova"}