Cisco Systems 3750E manual Default Ethernet Interface Configuration, 11-21

Chapter 11 Configuring Interface Characteristics

Configuring Ethernet Interfaces

Default Ethernet Interface Configuration

Table 11-3shows the Ethernet interface default configuration, including some features that apply only to Layer 2 interfaces. For more details on the VLAN parameters listed in the table, see Chapter 13, “Configuring VLANs.” For details on controlling traffic to the port, see Chapter 26, “Configuring Port-Based Traffic Control.”

Note To configure Layer 2 parameters, if the interface is in Layer 3 mode, you must enter the switchport interface configuration command without any parameters to put the interface into Layer 2 mode. This shuts down the interface and then re-enables it, which might generate messages on the device to which the interface is connected. When you put an interface that is in Layer 3 mode into Layer 2 mode, the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration.

Table 11-3	Default Layer 2 Ethernet Interface 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		VLAN 1 (Layer 2 interfaces only).
trunks)
VLAN trunking		Switchport mode dynamic auto (supports DTP) (Layer 2 interfaces
		only).
Port enable state		All ports are enabled.
Port description		None defined.
Speed		Autonegotiate. (Not supported on the 10-Gigabit interfaces.)
Duplex mode		Autonegotiate. (Not supported on the 10-Gigabit interfaces.)
Flow control		Flow control is set to receive: off. It is always off for sent packets.
EtherChannel (PAgP)		Disabled on all Ethernet ports. See Chapter 37, “Configuring
		EtherChannels and Link-State Tracking.”
Port blocking (unknown multicast		Disabled (not blocked) (Layer 2 interfaces only). See the
and unknown unicast traffic)		“Configuring Port Blocking” section on page 26-6.
Broadcast, multicast, and unicast		Disabled. See the “Default Storm Control Configuration” section
storm control		on page 26-3.
Protected port		Disabled (Layer 2 interfaces only). See the “Configuring
		Protected Ports” section on page 26-5.
Port security		Disabled (Layer 2 interfaces only). See the “Default Port Security
		Configuration” section on page 26-10.
Port Fast		Disabled. See the “Default Optional Spanning-Tree
		Configuration” section on page 20-12.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		11-21