O'Reilly logo

CCIE Routing and Switching Exam Certification Guide, Third Edition by Naren Mehta - CCIE No. 9797, Rus Healy - CCIE No. 15025, Wendell Odom - CCIE No. 1624

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Appendix F. Key Tables for CCIE Study

Chapter 1

Table 1-2. Ethernet Cabling Types

Type of Cable

Pinouts

Key Pins Connected

Straight-through

T568A (both ends) or T568B (both ends)

1 1; 2 2; 3 3; 6 6

Cross-over

T568A on one end, T568B on the other

1 3; 2 6; 3 1; 6 2

Table 1-3. Ethernet Header Fields

Field

Description

Preamble (DIX)

Provides synchronization and signal transitions to allow proper clocking of the transmitted signal. Consists of 62 alternating 1s and 0s, and ends with a pair of 1s.

Preamble and Start of Frame Delimiter (802.3)

Same purpose and binary value as DIX preamble; 802.3 simply renames the 8-byte DIX preamble as a 7-byte preamble and a 1-byte Start of Frame Delimiter (SFD).

Type (or Protocol Type) (DIX)

2-byte field that identifies the type of ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required