On Wed, 20 Sep 2000, Benny Leong (HTHK - Senior Engineer II - iServices Development, NNSD) wrote: > I am studying Bassam Halabi's Internet Routing Architecture. I don't > understand Figure 5-24 on page 173. Can anybody help to explain the detail > of the diagram ? Thanks. It's showing the effects of route maps. At the top is a series of routes coming from different ASes advertising different networks, six in all. The first light-grey line is the "match" clause, referring to an IP address access-list matching x.y.0.0/16. Two of the advertisements match, and are shown on the right, where they are tested by another match clause, for origin in AS3. Of these two, one matches, and is permitted with its MED set to 20 by a set clause. The other is denied by implicit deny. The four advertisements on the left that fail the initial match are then tested for a match with AS origin of 2 and IP address x.z.0.0/16. And so on. It's a sorting tree where each incoming advertisement is tested in a yes-no fashion against a rule, and depending on the outcome is either passed to another test, allowed unchanged, has an attribute changed, or is denied. At the end, three advertised routes are denied, two are accepted as-is, and one is accepted with its MED set to 20. For fun and practice, try to write a config snippet that matches the tree. Chapter 10 covers the actual configuration statements in detail. -- Jay Hennigan - Network Administration - [EMAIL PROTECTED] NetLojix Communications, Inc. NASDAQ: NETX - http://www.netlojix.com/ WestNet: Connecting you to the planet. 805 884-6323 **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _________________________________ 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]
