The question of "what kind of client is it?" is a relatively simple one if you ignore the associated questions of "what is it doing?" and "what does ISA provide for that request?", but we're not going to do that.
ISA Operating Modes:
Now select the Backup Route tab. This setting allows IE to use an alternate means to reach the Internet if the primary ISA server is unresponsive. There are two options:
That's it for today; feel free to contact me with comments.