background image
Chapter 5 655
6
What is NAT, and how can it help conserve IP addresses?
Network Address Translation (NAT) allows unregistered addresses in a private domain to
be translated to a registered public address.
7
List four benefits of address summarization.
Reduces the size of the routing table.
Hiding network changes.
Network growth.
Reduces router resource utilization.
8
What subnet mask is ideal for connecting WAN links?
255.255.255.252 (/30) mask. It provides two hosts. On the WAN, serial lines require only
two host addresses.
9
Define classful routing.
Classful routing observes the class address boundaries of Classes A, B, and C. Classful
routing protocols cannot carry variable-subnet mask information in their updates.
10
What is CIDR, and how does it offer greater flexibility in IP addressing?
Classless interdomain routing (CIDR) allows for the reduction of the size of routing tables
by creating aggregate routes, or supernets. CIDR eliminates the concept of network
classes and allows for better scalability when supporting the advertising of IP prefixes in
the Internet.
11
What is a discontiguous subnet?
A discontiguous subnet is two or more portions of a major network that are separated by
another major network.
12
True or false: To support variable-length subnet masking and route summarization, a
classless routing protocol must be incorporated into the design plan.
True.
13
Define classless routing.
Classless routing allows the prefix to be increased from the fixed classful length. Classless
routing allows prefixes to be greater than the classful specifications of 8, 16, and 24.
14
What is the prefix length of a Class A network?
8 bits.
87200333.book Page 655 Wednesday, August 22, 2001 1:41 PM