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Answers to the Chapter 4 "Do I Know This Already?" Quiz 715
34
Name at least three routing protocols.
IP RIP, IP IGRP, IP/IPX/AppleTalk EIGRP, IP OSPF, OSI NLSP, AppleTalk RTMP, Vines
VTP, OSI IS-IS are some examples of routing protocols
35
How does an IP host know what router to send a packet to? In which cases does an IP host
choose to send a packet to this router instead of directly to the destination host?
Typically an IP host knows to what router to send a packet based on its configured default
router. If the destination of the packet is in another subnet, the host sends the packet to the
default router. Otherwise, the host sends the packet directly to the destination host because
it is in the same subnet and, by definition, must be on the same data link.
36
How does an IPX host know which router to send a packet to? In which case does an IPX
host choose to send a packet to this router instead of directly to the destination host?
An IPX host knows which router to send a packet to by broadcasting a RIP request to
locate any servers or routers on the attached IPX network that have a route to the
destination network. If the destination is an IPX address on the attached network, a router
is not needed and the node forwards the packet directly instead of sending a RIP request.
37
Name three items in an entry in any routing table.
The group identifier, the interface by which to forward the packet, and the Layer 3 address
of the next router to send this packet to are three items that you will always find in a
routing table entry.
38
What OSI layer typically encapsulates using both a header and a trailer?
The data link layer typically encapsulates using both a header and a trailer. The trailer
typically includes a frame check sequence (FCS), which is used to perform error
detection.
Answers to the Chapter 4 "Do I Know This Already?" Quiz
1
What do the letters MAC stand for? What other terms have you heard to describe the same
or similar concept?
Media Access Control (MAC). Many terms are used to describe a MAC address: NIC,
LAN, hardware, burned-in, Universally Administered Address (UAA), Locally
Administered Address (LAA), Ethernet, Token Ring, FDDI, card, wire, and real are all
terms used to describe this same address in different instances.
2
What standards body owns the process of ensuring unique MAC addresses worldwide?
IEEE. The first half of the burned-in MAC address is a value assigned to the manufacturer
by the IEEE. As long as the manufacturer uses that prefix and doesn't duplicate values it
assigns in the last 3 bytes, global uniqueness is attained.
apA.fm Page 715 Monday, March 20, 2000 5:24 PM