Cisco Catalyst 250 Series Configuration Guide

Default SettingFeature
Enabled.
The switch might not support a pre-standard
powered device—such as Cisco IP phones
and access points that do not fully support
IEEE 802.3af—if that powered device is
connected to the switch through a crossover
cable. This is regardless of whether
auto-MIDX is enabled on the switch port.
Note
Auto-MDIX
Enabled (auto).Power over Ethernet (PoE)
Disabled on SFP module ports; enabled on all other
ports.
Keepalive messages
Interface Speed and Duplex Mode
Ethernet interfaces on the switch operate at 10, 100, 1000, or 10,000 Mb/s and in either full- or half-duplex
mode. In full-duplex mode, two stations can send and receive traffic at the same time. Normally, 10-Mb/s
ports operate in half-duplex mode, which means that stations can either receive or send traffic.
Switch models include Gigabit Ethernet (10/100/1000-Mb/s) ports, 10-Gigabit Ethernet ports, and small
form-factor pluggable (SFP) module slots supporting SFP modules.
Speed and Duplex Configuration Guidelines
When configuring an interface speed and duplex mode, note these guidelines:
•
The 10-Gigabit Ethernet ports do not support the speed and duplex features. These ports operate only
at 10,000 Mb/s and in full-duplex mode.
•
Gigabit Ethernet (10/100/1000-Mb/s) ports support all speed options and all duplex options (auto, half,
and full). However, Gigabit Ethernet ports operating at 1000 Mb/s do not support half-duplex mode.
•
For SFP module ports, the speed and duplex CLI options change depending on the SFP module type:
◦
The 1000BASE-x (where -x is -BX, -CWDM, -LX, -SX, and -ZX) SFP module ports support the
nonegotiate keyword in the speed interface configuration command. Duplex options are not
supported.
◦
The 1000BASE-T SFP module ports support the same speed and duplex options as the
10/100/1000-Mb/s ports.
For information about which SFP modules are supported on your switch, see the product release notes.
•
If both ends of the line support autonegotiation, we highly recommend the default setting of auto
negotiation.
•
If one interface supports autonegotiation and the other end does not, configure duplex and speed on both
interfaces; do not use the auto setting on the supported side.
Catalyst 2960-XR Switch Interface and Hardware Component Configuration Guide, Cisco IOS Release 15.0(2)EX1
22 OL-29420-01
Configuring Interface Characteristics
Interface Speed and Duplex Mode

Cisco Catalyst 250 Series Specifications

General

Brand	Cisco
Model	Catalyst 250 Series
Category	Switch
Language	English