Microsoft ISA 2006 Integrated NLB Mode and VirtualBox
Please remember if you are setting up an ISA Server 2006 NLB test environment that out of the box ISA server only supports unicast NLB mode. Most virtualization products like VMware (at least the last time I worked with it) and also VirtualBox only support multicast mode.
Main difference between the two modes is that unicast is a sort of hack to enable NLB by giving the same MAC address to different physical adaptors. In mulitcast mode a multicast MAC is added to all adaptors. Main advantage of the later is that mutlicast messages can be used for cluster heartbeat messages while unicast requires broadcasting of this information. So a heavy load might flood your switch infrastructure. On the other hand multicast mode requires switches supporting it and low-end devices usually don't.
Anyway, this is off topic. I just wanted to say that you need to enable multicast mode for ISA server networks if you want to test this in a VirtualBox environment. Otherwise you get unpredictable results. Once I enabled multicast mode everything worked as epxected.
One last thing. In cotrast to the documentation above I had to have NLB already enabled in the ISA MMC and virtual IPs assigned to my networks for the scripts to work.
About
Originally this site was intended as a project site. The goal was to define standards for the perimeterless network using
open-source software. To be honest I simply do not have the time for such a thing. So what is left is a blog with sporadic
posts that are either helpful for myself or I think are helpful for others, too since I had a hard time finding information
on the Internet. Think of it as a knowledge base.
Ehm yes, somtimes I write down my two cents on any topic that may go through my mind at that point in time ;-)