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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 8 Configuring Interface Characteristics
Configuring Layer 2 Interfaces
Default Layer 2 Ethernet Interface Configuration
Table 8-1 shows the Layer 2 Ethernet interface default configuration. For more details on the VLAN
parameters listed in the table, see Chapter 9, “Creating and Maintaining VLANs.” For details on
controlling traffic to the port, see Chapter 12, “Configuring Port-Based Traffic Control.”
Table 8-1 Default Layer 2 Ethernet Interface Configuration
Feature Default Setting
Operating mode Layer 2 or switching mode (switchport command).
Note Routing mode (no switchport command) is only an option
when the enhanced multilayer software image is installed.
All Catalyst 3550 Gigabit Ethernet switches ship with the
EMI installed. Catalyst 3550 Fast Ethernet switches can be
shipped with either SMI or EMI pre-installed. You can order
the Enhanced Multilayer Software Image Upgrade kit to
upgrade Catalyst 3550 Fast Ethernet switches from the SMI
to the EMI.
Allowed VLAN range VLANs 1 – 1005.
Default VLAN (for access ports) VLAN 1.
Native VLAN (for 802.1Q trunks) VLAN 1.
VLAN trunking Switchport mode dynamic desirable (supports DTP).
Port enable state All ports are enabled.
Port description None defined.
Speed Autonegotiate.
Duplex mode Autonegotiate.
Flow control Flow control set to off for receive and desired for send for
10/100/1000 Mb/s. For 10/100 Mb/s ports, send is always off.
EtherChannel (PAgP) Disabled on all Ethernet ports. See Chapter 21, “Configuring
EtherChannel.”
Port blocking (unknown multicast
and unknown unicast traffic)
Disabled (not blocked). See the “Configuring Port Blocking”
section on page 12-6.
Broadcast, multicast, and unicast
storm control
Disabled. See the “Default Storm Control Configuration” section
on page 12-3.
Protected port Disabled. See the “Configuring Protected Ports” section on
page 12-5.
Port security Disabled. See the “Default Port Security Configuration” section
on page 12-9.
Port Fast Disabled.
