Update README.md
diff --git a/xos/configurations/cord-pod/cdn/README.md b/xos/configurations/cord-pod/cdn/README.md
index 63606d4..a7730f9 100644
--- a/xos/configurations/cord-pod/cdn/README.md
+++ b/xos/configurations/cord-pod/cdn/README.md
@@ -57,6 +57,8 @@
 
 ### Test Commands
 
+* First, make sure the vSG is the only DNS server available in the test client. 
+* Second, make sure cdn_enable bit is set in CordSubscriber object for your vSG.
 * curl -L -vvvv http://downloads.onosproject.org/vm/onos-tutorial-1.1.0r220-ovf.zip > /dev/null
 * curl -L -vvvv http://onlab.vicci.org/onos-videos/Nov-planning-day1/Day1+00+Bill+-+Community+Growth.mp4 > /dev/null