Chapter 7. Kernel Support Tools

THIS CHAPTER EXAMINES TWO SUPPORT DAEMONS for Linux: pppd and rip2ad. pppd is the Point-to-Point Protocol (PPP) daemon that provides PPP support to the Linux kernel and Linux network processes. The pppd provides a transparent interface to the user; that is, network utilities and applications can be used without the utilities and applications having to have knowledge of the Point-to-Point Protocol or pppd.

pppd is a widely deployed Point-to-Point daemon for UNIX and Linux operating systems. Most versions of Linux use this version of pppd, with version 2.4.1 being the most recent release of the distribution. Before covering pppd, an overview of PPP and some design considerations will be presented.

rip2ad is a utility that allows Routing Information Protocol (RIP) advertisements to be sent out of an interface without running a full-blown routing daemon. rip2ad is an ideal tool on Linux routers that acts as an edge device that in turn acts as a gateway to RIP systems but does not require the complexity of RIP on the local systems.

We will begin with an overview of PPP, followed by sections on PPP for Linux and rip2ad.