ccna security interview questions

ccna security interview questions.. The routing protocol must include the subnet mask in the advertised route entry .. Routing decisions must be made based on the entire destination IP address; . To summarize multiple routing entries, a number of bits to their left must be the same (as shown in Table 7.1)Exam Points Keep in mind the above points related to implementing routing aggregation.7.2.4 Routing and Subnet MasksAs stated earlier, to take advantage of route summarization, the routing protocol used must include a subnet mask in the route entry. Otherwise, if multiple subnet masks are used in a classified network, the router will not know which subnet mask to route the packet based on.When using a classification protocol, this problem can be very apparent depending on the distribution of IP addresses in the network. When using classification protocols, the advertised routing updates contain only the network number, not the subnet mask. They assume that routers in other network segments belong to the same classification network and therefore know the subnet mask (which is configured on the router interface).At the boundary of two classified networks, the classification protocol automatically aggregates the subnets into classified network numbers (Class A, Class B, or Class C network numbers), as shown in the top half of Figure 7.9. As you can see, the classification protocol advertises only the network number (172.16.0.0), not the subnet mask. In addition, because subnet 172.16.1.0 is located at the border of two classified networks (172.16.0.0 and 192.168 0), this subnet is not advertised, but rather the classified network number 172.16.0.0. The bottom half of Figure 7.9 illustrates the behavior of classless protocols on the boundaries of classified networks (by default or after configuration). There are two things to note: subnet masks are included in routing updates; and routes are not automatically summarized on classified network boundaries.Chapter 7 VLSM 149RIPv2 and EIGRP take the behavior of the classification protocol by default, automatically summarizing on classified network boundaries, but you can manually disable this behavior. You can also configure specific summarized routes. OSPF, on the other hand, takes the behavior of a classless protocol by default and does not192.168.2.0/24