Default Layer 2 Ethernet Interface Vlan Configuration; Interaction With Other Features - Cisco 3020 - Catalyst Blade Switch Configuration Manual

Chapter 10 Configuring VLANs
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Default Layer 2 Ethernet Interface VLAN Configuration

Table 10-6
Table 10-6
Feature
Interface mode
Trunk encapsulation
Allowed VLAN range
VLAN range eligible for pruning
Default VLAN (for access ports)
Native VLAN (for IEEE 802.1Q trunks) VLAN 1
Configuring an Ethernet Interface as a Trunk Port
Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one
trunk port is configured on the switch and that this trunk port is connected to the trunk port of a second
switch. Otherwise, the switch cannot receive any VTP advertisements.
These sections contain this configuration information:
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Interaction with Other Features

Trunking interacts with other features in these ways:
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OL-8915-01
Make sure the native VLAN for an IEEE 802.1Q trunk is the same on both ends of the trunk link. If
the native VLAN on one end of the trunk is different from the native VLAN on the other end,
spanning-tree loops might result.
Disabling spanning tree on the native VLAN of an IEEE 802.1Q trunk without disabling spanning
tree on every VLAN in the network can potentially cause spanning-tree loops. We recommend that
you leave spanning tree enabled on the native VLAN of an IEEE 802.1Q trunk or disable spanning
tree on every VLAN in the network. Make sure your network is loop-free before disabling spanning
tree.
shows the default Layer 2 Ethernet interface VLAN configuration.
Default Layer 2 Ethernet Interface VLAN Configuration
Interaction with Other Features, page 10-17
Defining the Allowed VLANs on a Trunk, page 10-19
Changing the Pruning-Eligible List, page 10-20
Configuring the Native VLAN for Untagged Traffic, page 10-21
A trunk port cannot be a secure port.
Trunk ports can be grouped into EtherChannel port groups, but all trunks in the group must have the
same configuration. When a group is first created, all ports follow the parameters set for the first
port to be added to the group. If you change the configuration of one of these parameters, the switch
propagates the setting you entered to all ports in the group:
allowed-VLAN list.
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STP port priority for each VLAN.
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Default Setting
switchport mode dynamic auto
switchport trunk encapsulation negotiate
VLANs 1 to 4094
VLANs 2 to 1001
VLAN 1
Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide
Configuring VLAN Trunks
10-17