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664 Appendix A: Answers to Review Questions
23
Why is EIGRP considered a hybrid protocol?
EIGRP is considered a hybrid protocol because it has properties of link-state and distance-
vector protocols. EIGRP overcomes the typical limitations of distance-vector protocols.
EIGRP uses less bandwidth than most distance-vector protocols by sending updates only
when the network topology changes. EIGRP uses hello packets to determine neighbor
reachability.
24
What Cisco feature lets the percentage of bandwidth used by EIGRP be changed?
ip bandwidth-percent eigrp
25
What is the function of a designated router?
The designated router can send LSAs to the rest of the routers on the multiaccess
subnetwork. The designated router is the router with the highest priority.
26
Which protocols discussed in this chapter (OSPF, IGRP, EIGRP) are classful by default?
IGRP and EIGRP are classful by default. EIGRP can be configured to examine class by
using the no auto-summary command.
27
What provisions do OSPF and EIGRP make for security?
EIGRP and OSPF support router authentication. A router can be configured to accept
routing updates only from trusted sources. Both EIGRP and OSPF support MD5 and
clear-text authentication.
28
Name three features that are supported by OSPF and EIGRP.
Variable-length subnet masking.
Support for summarization.
Support for discontiguous networking.
Support for authentication.
29
What configuration command allows IGRP to support unequal-cost load balancing?
The variance command.
30
Of the three routing protocols (OSPF, IGRP, EIGRP), what protocol allows connectivity
to routers not manufactured by Cisco?
OSPF. OSPF is an IP standards-based routing protocol that has been adopted by all
vendors. IGRP and EIGRP are Cisco-proprietary.
87200333.book Page 664 Wednesday, August 22, 2001 1:41 PM