CCNA Cisco Certified Network Associate Study Guide - FTP Server

106 Chapter 3 � Internet Protocol
DNS is used to resolve Fully Qualified Domain Names (FQDNs), for
example, www.lammle.com or todd.lammle.com. An FQDN is a hierarchy
that can logically locate a system based on its domain identifier.
If you want to resolve the name “todd,” you either must type in the
FQDN of todd.lammle.com or have a device like a PC or router add the suffix
for you. For example, on a Cisco router, you can use the command ip
domain-name lammle.com to append each request with the lammle.com
domain. If you don’t do that, you’ll have to type in the FQDN to get the DNS
to resolve the name.
Bootstrap Protocol (BootP)
BootP stands for Bootstrap Protocol. When a diskless workstation is powered
on, it broadcasts a BootP request on the network. A BootP server hears
the request and looks up the client’s MAC address in its BootP file. If it finds
an appropriate entry, it responds by telling the machine its IP address and the
file—usually via the TFTP protocol—it should boot from.
BootP is used by a diskless machine to learn the following:
� Its own IP address
� The IP address and host name of a server machine
� The boot filename of a file that is to be loaded into memory and executed
at boot-up
BootP is an old program that isn’t used anymore, right? Wrong: BootP is
still around, but now we just call it the Dynamic Host Configuration Protocol,
which you will learn about in the next section.
Dynamic Host Configuration Protocol (DHCP)
The Dynamic Host Configuration Protocol (DHCP) gives IP addresses to
hosts. It allows easier administration and works well in small–to–even-verylarge
network environments. All types of hardware can be used as a DHCP
server, including a Cisco router.
DHCP differs from BootP in that BootP gives an IP address to a host, but
the host’s hardware address must be entered manually in a BootP table. You
can think of DHCP as a dynamic BootP. However, remember that BootP is
also used to send an operating system that a host can boot from. DHCP cannot
perform this function.