Implementing a WPAD to PAC redirection without usig the proxy as DNS server.

Assumptions:

• internal domain is corp.local
• explict proxy FQDN is proxy.corp.local
• explict proxy IP is 192.168.1.1
• accelerated PAC is hosted on ProxySG

Requrements:

• DHCP server option 252 WPAD is configured, string: http://proxy.corp.local/accelerated_pac_base.pac
• internal DNS server resolve wpad.corp.local to 192.168.1.1
• client have dns-suffix corp.local configured
• port 80 on ProxySG configured to explict HTTP proxy
• local policy on ProxySG (CPL see below)

<Proxy>
  url=http://wpad/wpad.dat action.rewrite_pac(yes)
  define action rewrite_pac
  rewrite(url,"^http://wpad.wpad.dat","https://192.168.1.1:8082/accelerated_pac_base.pac")
  end

Internet Explorer tries to connect to http://wpad/wpad.dat, then to http://wpad.corp.local (dns-suffix).
Client connects to ProxySG port 80 (because FQDN is resolved to ProxySG's IP-address).
Local policy rewrites request to accelerated PAC.