Default Layer 2 Lan Interface Configuration - Cisco 7609 Configuration Manual

Chapter 7 Configuring LAN Ports for Layer 2 Switching
Note DTP is a point-to-point protocol. However, some internetworking devices might forward DTP frames
improperly. To avoid this problem, ensure that LAN ports connected to devices that do not support DTP
are configured with the access keyword if you do not intend to trunk across those links. To enable
trunking to a device that does not support DTP, use the nonegotiate keyword to cause the LAN port to
become a trunk but not generate DTP frames.

Default Layer 2 LAN Interface Configuration

Table 7-3
Table 7-3
Feature
Interface mode:
•
•
Trunk encapsulation
Allowed VLAN range
VLAN range eligible for pruning
Default VLAN (for access ports)
Native VLAN (for 802.1Q trunks)
Spanning Tree Protocol (STP)
STP port priority
STP port cost
78-14064-04
shows the Layer 2 LAN port default configuration.
Layer 2 LAN Interface Default Configuration
Before entering the switchport command Layer 3 (unconfigured)
After entering the switchport command
Default
switchport mode dynamic desirable
switchport trunk encapsulation negotiate
• With Release 12.1(13)E and later releases,
VLANs 1 to 4094, except reserved VLANs (see
Table 9-1 on page
With 12.1 E releases earlier than
•
Release 12.1(13)E, VLANs 1 to 1005
VLANs 2 to 1001
VLAN 1
VLAN 1
Enabled for all VLANs
128
• 100 for 10-Mbps Ethernet LAN ports
19 for 10/100-Mbps Fast Ethernet LAN ports
•
19 for 100-Mbps Fast Ethernet LAN ports
•
4 for 1,000-Mbps Gigabit Ethernet LAN ports
•
2 for 10,000-Mbps 10-Gigabit Ethernet LAN
•
ports
Cisco 7600 Series Router Cisco IOS Software Configuration Guide—12.1E
Default Layer 2 LAN Interface Configuration
9-2)
7-5