I have done this. I will look for my .pac file I created. It has been awhile and we no longer use it. We use WCCP.
isn´t the "Sharp Super Proxy" proxy.pac that flies around the internet since a couple of years the right thing here?
This proxy.pac builds a hash on the URL or URL path and picks one proxy of a given list of proxy servers per URL. This will share the load across the available proxy servers and ensures that the same URL is always called through the same proxy, which is usually what you want to prevent problems that may occur without sessions stickiness.
For each URL it replies back with a list of proxy servers, so if the first one is not available the browser will automatically use the second one, so you got load sharing, session persistency and fail-over.
Honestly I am not sure about the disadvantages, but I have seen customers using the script before. Maybe someone else has some experience with it.
is there another way possible for loadbalancing not using a PAC File?
Normally PAC Files are working fine. We have customers using PAC Files with more than 600!! Code Lines. :-)
They are still working but very tricky.
Are your users using different browser types or other OS like Windows??
Depending on the security reasons load balancing without pac file makes more sense.
WCCP: Load Balancing and Load Sharing is included. But WCCP has limitations, authentication is not so easy. But any internet traffic from any application is routed to the proxy.
Proxy HA: When using MWG 7.2.x i would prefer the HA Cluster. When using the HA Cluster you just have to add one proxy ip into your pac file.
McAfee Client Proxy and Proxy HA: You don´t have to configure any proxy setting on your browsers or applications. MCP forwards any traffic to the HA proxy ip.
So, there are different ways for loadbalancing. It depends on some other circumstances which solution best fits to your envirionment.
Why do you have to use the DNS Name?
you can use round robin DNS with CNAME
proxy = round robin with CNAME dnsname1.test.com and dnsname2.test.com
and you can use proxy in your pac file