A couple of thoughts: 1. The IOS specific parts of both Inside Cisco IOS Software Architecture are still pretty relevant. The RIB is now a separate process, and there are other changes, but the software architecture (of IOS specifically!) is pretty close to what's there. 2. The hardware architecture isn't current, but, IMHO, those sections are still "useful," for understanding the general way routers are laid out in terms of driver to ASIC interaction, packet receive processing, and things like that. 3. I've been talking to folks in Cisco to encourage them to write a new version. I'm busy on another project (The Art of Network Architecture), and have a couple of other ideas backed up in my mind to work on, and don't have access to the code or hardware architecture folks any longer, so it would be difficult for me. I would be glad to help anyone in cisco who wants to pull such a book together in any way I can, but I'm just not in a position to actually write an updated version of this pair of books. HTH Russ -- <>< riwhite@verisign.com russw@riw.us