Unfortunately the WSA cannot control which requests get sent to it, it simply listens for traffic coming to its interface on specific ports (80, 3128, 21, 443). When it comes to specific URLs being routed to one WSA or another it will require that you have a device that can inspect the traffic at Layer 4 (HTTP/HTTPS/FTP) and make a routing decision based on the URI in the HTTP header.
You could add a 3rd WSA to route the traffic using an upstream proxy configuration. You would use proxy groups and routing policies to match Custom URL categories or predefined URL categories to send to one of the two upstream proxies.
Other than adding an additional device to route the traffic, you could look into Policy based routing or using multiple WCCP services (one for each WSA) and creating an ACL to match the business sites IP addresses vs the non-business sites. This could become an issue as most websites use dynamic IP schemes.
One other method i wanted to mention was the use of a PAC or WPAD file. These types of files would allow you to configure statements to match domains and send to a specific WSA. The WSA also has the ability to host these files if you do not have better method of hosting them (i.e. DNS).
you mean i 1st point that can i purchase 3 WSA and Make one as Priamry and the 2econd and 3rd as upstream Proxy
and I can Route based in URL catagroy as exmaple the Busines Catagory routed through 2econd WSA and the non business Catagory Routed via 3rd WSA and in this case the User will take the Primary Proxy in Internet browser seeting ?
Yes, you could either use an explicit setting (browser config/PAC/WPAD) or transparent (WCCP/PBR) to point to the first proxy and then the first proxy will route based on category to one of the two upstream proxies based on your policy configuration.
Depending on what DR requirements you have, for load balancing/failover you would probably need 6 appliances total. 2 for the main proxy to either loadbalance with WCCP/physical load balancer or to have a backup in case of failover, and then the possibility of needing a backup for each of the upstream proxies.
The WSA's are in active/active mode and will require the failover be setup in whatever mechanism you are using to direct traffic to them (PAC/WPAD, load balancer, firewall, router, etc...)
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...