Administrator Guide

source MAC addresses. The information that is preserved as the frame moves through the network. The
below figure shows the structure of a frame with a tag header. The VLAN ID is inserted in the tag header.
Figure 49. Tagged Frame Format
The tag header contains some key information used by Dell Networking OS:
• The VLAN protocol identifier identifies the frame as tagged according to the IEEE 802.1Q specifications
(2 bytes).
• Tag control information (TCI) includes the VLAN ID (2 bytes total). The VLAN ID can have 4,096 values,
but two are reserved.
NOTE
: The insertion of the tag header into the Ethernet frame increases the size of the frame to more
than the 1518 bytes specified in the IEEE 802.3 standard. Some devices that are not compliant with IEEE
802.3 may not support the larger frame size.
Information contained in the tag header allows the system to prioritize traffic and to forward information to
ports associated with a specific VLAN ID. Tagged interfaces can belong to multiple VLANs, while untagged
interfaces can belong only to one VLAN.
Configuring VLAN Membership
By default, all Aggregator ports are member of all (4094) VLANs, including the default untagged VLAN 1. You
can use the CLI or CMC interface to reconfigure VLANs only on server-facing interfaces (1–8) so that an
interface has membership only in specified VLANs.
To assign an Aggregator interface in Layer 2 mode to a specified group of VLANs, use the vlan tagged and
vlan untagged commands. To view which interfaces are tagged or untagged and to which VLAN they
belong, use the show vlan command (Displaying VLAN Membership).
To reconfigure an interface as a member of only specified tagged VLANs, enter the vlan tagged command
in INTERFACE mode:
1 Add the interface as a tagged member of one or more VLANs, where: vlan-id specifies a tagged VLAN
number. Range: 2-4094.
INTERFACE mode
vlan tagged {vlan-id }
To reconfigure an interface as a member of only specified untagged VLANs, enter the vlan untagged
command in INTERFACE mode:
1 Add the interface as an untagged member of one or more VLANs, where: vlan-id specifies an untagged
VLAN number. Range: 2-4094.
Interfaces 414