As traffic for an Internet Web site grows, there is a need to scale Web sites by adding additional servers. Eventually, the best way to scale the site is to mirror the site at multiple locations around the Internet. Mirroring sites on the Internet solves the scaling problem but introduces the problem of routing users to the best site. This is also referred to as content routing.There are multiple solutions to the content routing problem. The first is to redirect a client to an alternative Web site using Hypertext Transfer Protocol (HTTP) redirects. This unfortunately works only for Web connections; it does not support other applications, including audio and video streaming. The alternative is to redirect the client to a site using Domain Name System (DNS). This is the most flexible method of redirecting a client.The Cisco Content Router 4400 (CR4400) is designed to load balance 2 to 20 sites on the Internet. The CR4400 uses DNS to redirect a client to the best site on the Internet based on network delay. The CR4400 uses a process called Boomerang to have each site respond to a DNS query with the IP address of a server at the site. The first response through the network wins the race and is used by the client to connect to a server at the site.