Checking an access list does introduce a significant overhead. If the router had multilple LAN interfaces and only some traffic was to be routed over the serial interfaces , then you may not wish to incurr the overhead of having every frame leaving the lan processed for the access list, in which cas it makes more sense to put it on the outbound serial interfaces.
In my poing of view, the interpretation of the statement "The access list shd be put closer to the packet source" is different. Actually, it is talking closer in terms of router, not in terms of interfaces. If you read first line of page 508, it says "It is close to the source, being in R3." The statement doesn't talk about the interfaces at all. Also, it doesn't matter much, whether it is on serial or ethernet, because in any case, all the packets coming from Bob's pc will be checked once at serial/ethernet interface. May be, the author put on serial to maintain the consistency with other examples.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...