144 Chapter 4: Bridges/Switches and LAN Design
With the advent of Fast Ethernet and Gigabit Ethernet, the variety of Ethernet standards has
increased to the point that most networking personnel do not memorize all the standards.
However, the CCNA exam will require you to be very familiar with Ethernet standards,
or at least the standards for 10- and 100-Mbps Ethernet. Table 4-5 lists the key Ethernet
specifications and several related details about the operation of each.
1.
For entire bus, without using a repeater
2.
From device to hub/switch
3.
Numbers shown are for half or full duplex
Token Ring
IEEE 802.5
IEEE 802.2
IBM helped with development
before the IEEE took over.
FDDI
ANSI X3T9.5
IEEE 802.2
ANSI liked 802.2, so it just
refers to the IEEE spec.
Table 4-5
Ethernet Standards
Standard
MAC Sublayer
Specification
Maximum Cable
Length
Cable Type
Pairs
Required
10Base5
802.3
500 m
1
50-Ohm thick coaxial
cable
--
10Base2
802.3
185 m
1
50-Ohm thin coaxial
cable
--
10BaseT
802.3
100 m
1
Category 3, 4, or 5
UTP
2
10BaseFL
802.3
2000 m
2
Fiber
1
100BaseTx
802.3u
100 m
2
Category 5 UTP
2
100BaseT4
802.3u
100 m
2
Category 3 UTP
4
100BaseT2
802.3u
100 m
2
Category 3, 4, or 5
UTP
2
100BaseFx
802.3u
400/2000 m
3
Multimode fiber
1
100BaseFx
802.3u
10,000m
Single-mode fiber
1
1000BaseSx
802.3z
220-550m
Multimode fiber
1
1000BaseLx
802.3z
3000m
Single-mode or
multimode fiber
1
1000BaseCx
802.3z
25m
Shielded copper
2
1000BaseT
802.3ab
100m
Category 5 UTP
2
Table 4-4
MAC and LLC Details for Three Types of LANs (Continued)
Name
MAC Sublayer
Spec
LLC Sublayer
Spec
Other Comments
ch04.fm Page 144 Monday, March 20, 2000 5:02 PM