Speed - Cisco catalyst 3750 Command Reference Manual

Chapter 2 Catalyst 3750 Switch Cisco IOS Commands

speed

Use the speed interface configuration command to specify the speed of a 10/100 Mb/s or
10/100/1000 Mb/s port. Use the no or default form of this command to return the port to its default
value.
Syntax Description
10
100
1000
auto
nonegotiate
Defaults
The default is auto.
Command Modes Interface configuration
Command History Release
12.1(11)AX
12.2(20)SE1
Usage Guidelines You cannot configure speed on the 10-Gigabit Ethernet ports.
Except for the 1000BASE-T SFP modules, if an SFP module port is connected to a device that does not
support autonegotiation, you can configure the speed to not negotiate (nonegotiate).
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed
setting and then forces the speed setting to the negotiated value. The duplex setting remains as
configured on each end of the link, which could result in a duplex setting mismatch.
If both ends of the line support autonegotiation, we highly recommend the default autonegotiation
settings. If one interface supports autonegotiation and the other end does not, do use the auto setting on
the supported side, but set the duplex and speed on the other side.
Changing the interface speed and duplex mode configuration might shut down and re-enable the
Caution
interface during the reconfiguration.
OL-8552-07
speed {10 | 100 | 1000 | auto [10 | 100 | 1000] | nonegotiate}
no speed
Port runs at 10 Mb/s.
Port runs at 100 Mb/s.
Port runs at 1000 Mb/s. This option is valid and visible only on 10/100/1000
Mb/s-ports.
Port automatically detects the speed it should run at based on the port at the other
end of the link. If you use the 10, 100, or 1000 keywords with the auto keyword, the
port only autonegotiates at the specified speeds.
Autonegotiation is disabled, and the port runs at 1000 Mb/s. (The 1000BASE-T SFP
does not support the nonegotiate keyword.)
Modification
This command was introduced.
Support for the 10, 100, and 1000 keywords with the auto keyword was added.
Catalyst 3750 Switch Command Reference
speed
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