Master password is used by Intergration server for authenticating while connecting to different clients… you can go thorugh the IS Administration Guide for more details on that…
This passwrod expiry interval is by default 90 days which you can change by setting it to any finite value , if you will set this interval = 0 master passwrod will never expire (though its not recommended).
-nD
#webMethods#Integration-Server-and-ESB#webMethods-Archive