Cisco WS-C4003 Software Guide - Page 69
Configuring Gigabit Ethernet Switching, Understanding How Gigabit Ethernet Works
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CH A P T E R 5 Configuring Gigabit Ethernet Switching This chapter describes how to configure Gigabit Ethernet switching on the Catalyst enterprise LAN switches. The configuration tasks in this chapter apply to Gigabit Ethernet switching modules, fixed-configuration switches, and uplink ports on the supervisor engine. Note For complete syntax and usage information for the commands used in this chapter, refer to the Command Reference-Catalyst 4000 Family, Catalyst 2948G, and Catalyst 2980G Switches. This chapter consists of these sections: • Understanding How Gigabit Ethernet Works, page 5-1 • Default Gigabit Ethernet Configuration, page 5-6 • Configuring Gigabit Ethernet, page 5-6 Understanding How Gigabit Ethernet Works These sections describe how Gigabit Ethernet works: • Understanding How Gigabit Ethernet Flow Control Works, page 5-1 • Understanding How Port Negotiation Works, page 5-3 • Understanding How Oversubscribed Gigabit Ethernet Works, page 5-3 Understanding How Gigabit Ethernet Flow Control Works These sections describe how flow control works: • Flow-Control Overview, page 5-1 • Sending and Receiving Pause Frames, page 5-2 • Using Flow-Control Keywords, page 5-2 Flow-Control Overview Flow-control is a feature that Gigabit Ethernet ports use to inhibit the transmission of incoming packets. If a buffer on a Gigabit Ethernet port runs out of space, the port transmits a special packet that requests remote ports to delay sending packets for a period of time. This special packet is called a pause frame. 78-12647-02 Software Configuration Guide-Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4 5-1
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