Sec3: Ethernet And Cabling

CCNA 200-125, ICND1, Sec. 2: c

- UTP and STP

UTP is Unshielded Twisted Pair and good for EMI

STP is shielded twisted pare and vulnerable and expensive.

- Cooper Cable

10BASE-T/ IEEE 802.3/ 10Mbps/ 2 Pair

100BASE-T/ IEEE 802.3u/ 100Mbps/ 2 Pair

1000BASE-T/ IEEE 802.3ab/ 1000Mbps/ 4 Pair

10GBASE-T/ IEEE802.3an/ 10Gbps/4 Pair

- Fiber Optic

1000BASE-LX/ IEEE 802.3z/ 1000Mbps/

- Crossover and straight-through cable

- Straight-through for connection between other devices

Connection between switch and host(pc)

- Crossover cable for like devices

Connection between switch and switch

- Cable for Gigabit Ethernet

as Gigabit Ethernet use 4 pair (8 wire) at the same time, But there is no need to use crossover cable for that.

Connection using Gigabit Ethernet

- Auto MDI-X

For CCNA exam, we need to keep the role that written above. But in real world, this technology enable to do that without specific cable.

To enable it, set speed, duplex and mdix set to auto

int f 0/1
speed auto
duplex auto
mdix auto

- The Ethernet Header

Which consist of Preamble, SFP(Start Frame Delimiter), Destination Mac address, Source Mac address

- Preamble

Indicate start point, 10101010 * 7

- SFD

Indicate end of preamble, start of destination mac address. 10101011

- Destination MAC address

- Source MAC address

- Protocol type

Normally indicate IPv4, sometimes IPv6

- The Ethernet Trailer

The trailer comes at the end of data frame.

- FCS (Frame Check Sequence)

Error detection.