672 Appendix A: Answers to Review Questions
8
If I have a measurement interval of .125 seconds, and I am guaranteed a CIR of 8k during
that time period, what is my overall CIR?
64k (.125 = 8 intervals of 8k).
9
In a full-mesh environment, should Inverse ARP be disabled?
Yes.
10
Can split horizon be turned off for IPX RIP and AppleTalk RTMP?
No.
11
Does OSPF apply the split horizon rule?
No. Every router has a copy of the database.
12
Name two good reasons to use subinterfaces.
So that different parameters can be applied to each subinterface
Split horizon issues are hard to troubleshoot.
13
What does NBMA stand for?
Nonbroadcast multiaccess.
14
If four sites are fully meshed, how many links are needed?
6. Using the formula n
Ч (n 1) / 2, 4 Ч (4 1) / 2 = (4 Ч 3) / 2 = 12 / 2 = 6.
15
What two routing protocols are used for fast convergence?
OSPF and EIGRP.
16
Can there be different LMI types on subinterfaces?
No. LMI types are set on the physical interfaces, not the subinterfaces.
17
What is the maximum Frame Relay transmittable unit (MTU) size?
1500 bytes. Frame Relay sends packets up to this size without fragmentation and
reassembly. To test if packets of various sizes are being fragmented, use Cisco's Extended
IP ping, pick a packet size, and set the don't fragment (DF) bit. This makes the ping fail
if Frame Relay is trying to fragment the packet, and you can find the true MTU packet size
for your Frame Relay circuit.
18
When is LMI exchanged between the router and the carrier?
LMI keepalives are exchanged every 10 seconds. Full status inquiries are exchanged every
60 seconds.
87200333.book Page 672 Wednesday, August 22, 2001 1:41 PM