The diversion/interception of a TCP connection creates several issues. First, the original destination IP and port must somehow be communicated to the proxy. This is not always possible (e.g., where the gateway and proxy reside on different hosts). There is a class of cross-site attacks that depend on certain behavior of intercepting proxies that do not check or have access to information about the original (intercepted) destination. This problem may be resolved by using an integrated packet-level and application level appliance or software which is then able to communicate this information between the packet handler and the proxy.