Duplex Mode On Fast Ethernet Interfaces; Fast Ethernet Interface Speed; Link Autonegotiation On Ethernet Interfaces - Cisco 6000 Series Configuration Manual

Configuring Ethernet Interfaces
For more information on HSRP, see the Implementing HSRP module of IP Addresses and Services
Configuration Guide.

Duplex Mode on Fast Ethernet Interfaces

Fast Ethernet ports support the duplex transmission type. Full-duplex mode enables the simultaneous data
transmission between a sending station and a receiving station, while half-duplex mode enables data
transmission in only one direction at a time.
When configuring duplex mode on a Fast Ethernet interface, keep the following in mind:
• If auto-negotiation is enabled on the interface, the default is duplex negotiated.
• If auto-negotiation is disabled on the interface, the default is full-duplex.
Note
You can configure duplex mode on Fast Ethernet interfaces only. Gigabit Ethernet and 10-Gigabit Ethernet
interfaces always run in full-duplex mode.

Fast Ethernet Interface Speed

You can configure the interface speed on Fast Ethernet interfaces. Keep the following in mind when configuring
the speed for a Fast Ethernet interface:
• If auto-negotiation is enabled on an interface, the default is speed negotiated.
• If auto-negotiation is disabled on an interface, the default speed is the maximum speed allowed on the
Note
Both ends of a link must have the same interface speed. A manually configured interface speed overrides any
auto-negotiated speed, which can prevent a link from coming up if the configured interface speed at one end
of a link is different from the interface speed on the other end.

Link Autonegotiation on Ethernet Interfaces

Link autonegotiation ensures that devices that share a link segment are automatically configured with the
highest performance mode of interoperation. Use the negotiation auto command in interface configuration
mode to enable link autonegotiation on an Ethernet interface. On line card Ethernet interfaces, link
autonegotiation is disabled by default.
Note The negotiation auto command is available on Gigabit Ethernet and Fast Ethernet interfaces only.
This table describes the performance of the system for different combinations of the duplex and speed modes.
The specified duplex command configured with the specified speed command produces the resulting system
action, provided that you have configured autonegotiation on the interface.
Interface and Hardware Component Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
interface.
Duplex Mode on Fast Ethernet Interfaces
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