R1 has 5 working interfaces, with EIGRP neighbors existing off each interface. R1 has
routes for subnets 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24, with EIGRP integer metrics of
roughly 1 million, 2 million, and 3 million, respectively. An engineer then adds the ip
summary-address eigrp 1 10.1.0.0 255.255.0.0 command to interface Fa0/0. Which of the
following is true?

A.
R1 loses and then reestablishes neighborships with all neighbors.

B.
R1 no longer advertises 10.1.1.0/24 to neighbors connected to Fa0/0.

C.
1 advertises a 10.1.0.0/16 route out Fa0/0, with metric of around 3 million
(largest metric of component subnets).

D.
R1 advertises a 10.1.0.0/16 route out Fa0/0, with metric of around 2 million
(median metric of component subnets).

Explanation:
The ip summary-address command does reset neighborships, but only on the interface
under which it is configured. After those neighborships come up, R1 will advertise the
summary route, but none of the subordinate routes inside that summary. The summary route
will us a metric equal to the metric of the lowest metric subordinate route, approximately
1,000,000 in this casE.