chosen on the ISDN B channel because it provides CHAP authentication. LAPB is used on the
link with known continuing high error rates so that LAPB can recover data lost going across the
link. Because the problem statement also requests three different encapsulations, HDLC was
chosen.
deduce a fact from a limited amount of information. The final question in this scenario requires
that you think beyond the topic of serial encapsulations. PPP control protocols are used by
Boston on the PPP link to discern the Layer 3 addresses on the other end of the link. However,
LAPB and HDLC do not perform this function. CDP is enabled on each of these links by default
and is sending messages to discover information about Boston's neighbors. Also, Boston
examines the source address of routing updates to learn the Layer 3 addresses of its neighbors.
choices most likely are different. However, you should have one subnet per VC when using only
point-to-point subinterfaces. With the original criteria of Routers A, D, and E each using
no ip domain-lookup
ipx routing 0200.dddd.dddd
!
isdn switch-type basic-dms100
username Boston password Larry
!
interface BRI 0
encapsulation ppp
ip address 200.1.5.14 255.255.255.252
ipx network 204
isdn spid1 22255522220
ppp authentication chap
!
dialer-group 1
dialer idle-timeout 120
dialer map ip 200.1.5.13 name Boston 11115551111
!
interface ethernet 0
ip address 200.1.4.1 255.255.255.0
ipx network 104
!
router igrp 1
network 200.1.4.0
network 200.1.5.0
!
dialer-list 1 protocol ip permit