i saw a book "cisco ios software architecture" really good book to how cisco router work, but too expensive.. if you're working with cisco, i think it would be free Thks/Brdgs Stefan __________________________________________________ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]