9-14
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 9 Configuring Interfaces
Configuring Ethernet Interfaces
Configuring Interface Speed and Duplex Mode
Ethernet interfaces on the switch operate at 10, 100, or 1000 Mb/s or 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 combinations Gigabit Ethernet (10/100/1000-Mb/s) ports and small form-factor
pluggable (SFP) module slots supporting SFP modules.
•
Speed and Duplex Configuration Guidelines, page 9-14
•
Setting the Interface Speed and Duplex Parameters, page 9-15
Speed and Duplex Configuration Guidelines
When configuring an interface speed and duplex mode, note these guidelines:
•
You can configure interface speed on Gigabit Ethernet (10/100/1000-Mb/s) ports. You can configure
Gigabit Ethernet ports to full-duplex mode or to autonegotiate. You also can configure Gigabit
Ethernet ports to half-duplex mode if the speed is 10 or 100 Mb/s. Half-duplex mode is not
supported on Gigabit Ethernet ports operating at 1000 Mb/s.
•
You cannot configure speed on SFP module ports or on 10 Gigabit Ethernet ports, but you can
configure speed to not negotiate (nonegotiate) if connected to a device that does not support
autonegotiation.
Table 9-2
Default Ethernet Configuration
Feature
Default Setting
Operating mode
Layer 2 or switching mode (switchport command).
Allowed VLAN range
VLANs 1– 4094.
Default VLAN (for access ports)
VLAN 1 (Layer 2 interfaces only).
Native VLAN (for IEEE 802.1Q trunks)
VLAN 1 (Layer 2 interfaces only).
VLAN trunking
Switchport mode access (Layer 2 interfaces only).
Port enable state
Enabled.
Port description
None defined.
Speed
Autonegotiate.
Duplex mode
Autonegotiate.
IEEE 802.3x flow control
Flow control is set to receive: off. It is always off for sent packets.
EtherChannel Disabled
on
all Ethernet ports. See
Chapter 28, “Configuring
EtherChannels.”
Broadcast, multicast, and unicast storm control
Disabled. See the
“Default Storm Control Configuration” section on
page 19-3
.
Port Fast
Disabled. See the
“Default Optional Spanning-Tree Configuration”
section on page 15-5
.
Auto-MDIX
Enabled.
Cisco Discovery Protocol (CDP)
Enabled.