for gradual network upgrades and usually does not require rewiring the whole
network. Nearly every known 100BASE-T NIC and most generic NICs are
compatible with Linux. 100BASE-T requires Category 5 UTP cabling.
1000BASE-T
1000BASE-T—usually referred to as Gigabit Ethernet—is the accepted
standard in enterprise networking, with most NICs being detected and
configured correctly by Ubuntu. Like 100BASE-T NICs, gigabit NICs
automatically downgrade if they are plugged in to a slower network. Also as
with 100BASE-T, gigabit NICs require Category 5 UTP cabling; however,
many institutions are now deploying Category 6 cables, which have much
longer range and so are often worth the extra cost. You will find that most
newer computers are sold with gigabit NICs.
Fiber-Optic and Gigabit Ethernet
Fiber-optic is more commonly used in newer and high-end installations
because the cost of upgrading can be prohibitive for older sites.
Fiber-optic cable was originally used on fiber distributed data interface
(FDDI) networks, similar to Token Ring in structure except that there are two
rings (one primary, the other secondary). The primary ring is used
exclusively, and the secondary sits idle until there is a break in the primary
ring. That is when the secondary ring takes over, keeping the network alive.
FDDI has a speed of 100Mbps and has a maximum ring length of 100
kilometers (62 miles). FDDI uses several tokens at the same time that, along
with the faster speed of fiber optics, account for the drastic increase in
network speed.
As stated earlier, switching to a fiber-optic network can be very costly. To
make the upgrade, the whole network has to be rewired, and all NICs must be
replaced at the same time. Most FDDI NICs are recognized by Linux.
Fiber-related gigabit that uses fiber optics is termed 1000BASE-X, whereas
1000BASE-T Gigabit Ethernet uses twisted-pair cabling (see the “Unshielded
Twisted Pair” section, later in this chapter).
Wireless Network Interfaces
Wireless networking, as the name states, works without network cables; it is
an extremely popular option. Upgrading is as easy as replacing network cards
and equipment, such as routers and switches. Wireless networking equipment