看来DynDNS Client 还有火墙功能，it ask me to define defense plan. Do not know if this is good or not.
The message is as following:
CNAME www.verycd.com is in the following categories: Spyware, Peer-to-Peer, Hacking.
lb.verycd.shicent.com is not in any categories.
Hosts in the Phishing, Spyware, and Conficker Worm categories are blocked by default if you do not have a defense plan.
To change your settings, you'll need to create a network and defense plan. If you already have a defense plan, you can modify it.