CCENT/CCNA ICND1 100-101 Official Cert Guide

Verifying Manually Summarized Routes

Route summarization impacts the routing tables on the routers, with different results depending on whether a router simply learned the summary or whether the router created the summary. Example 21-1 shows R1’s routing table, both before the summary route was configured on R3 (as shown in Figure 21-1) and then after R3 added the summary route configuration (as shown in Figure 21-2). (Note that the example shows only the routes learned by the routing protocol, rather than including the connected routes.)

Example 21-1 R1 Routing Table: Before and After Summary Route Was Learned

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! First, the before caseR1# show ip route rip! (Legend lines omitted for brevity)     10.0.0.0/8 is variably ...