There are already several standard and well documented methods for creating a NLB cluster for BAM Portal like here. The problem with all these methods is that they tend to be very complex and long. Usually you would end up missing some steps and it will not work.
What I was able to find is a very simple and short way to configure BAM portal on several servers using Windows NLB.
Use the BAM Management Utility to get the current BAM configuration. To do this, click Start, click Run, and type drive:\Program Files\Microsoft BizTalk Server 2010\Tracking\bm get-config -FileName:MyConfig.xml.
Replace the local host name with the name of the NLB cluster. To do this, click Start, click Run, and type notepad drive:\Program Files\Microsoft BizTalk Server 2010\Tracking\MyConfig.xml.
For hardware-based NLB only, verify the configuration file has the following:
<GlobalProperty Name="BAMVRoot"> http://<NLB IP Address>:portname/BAM</GlobalProperty>
Modify the following line to point to the NLB cluster by replacing the computer name (machinename) with the cluster name:
<GlobalProperty Name=" BAMVRoot"> http://machinename:portname/BAM </GlobalProperty>
Save the new configuration. To do this, click Start, click Run, and type drive:\Program Files\Microsoft BizTalk Server 2010\Tracking\bm update-config -FileName:MyConfig.xml.
thank you
Very nice article boss, Thank you very mutch.