Hi all..

i installed 2 squid proxy server..
proxy-a and proxy-b and use proxy.pac to make this 2 server redundant.
my problem is.. its takes too long (about 10-15 minute to change from proxy-a to proxy-b when proxy-a is down) . proxy-a is the default server that proxy.pac will connect..

my proxy.pac file is like this :

function FindProxyForURL(url, host) {
      // our local URLs from the domains below example.com don't need a proxy:
      if (shExpMatch(url,"*.iwan.com/*"))                  {return "DIRECT";}
      if (shExpMatch(url, "*.iwan.com:*/*"))               {return "DIRECT";}
      // All other requests go through port 8080 of proxy.example.com.
      // should that fail to respond, go directly to the WWW:
   	return "PROXY; PROXY";	

anybody can help??
thanks in advance..