FTOS Configuration Guide for the C-Series - Force10 Networks

Configuring a VLAN-Stack VLAN
After you configure VLAN-Stack access and trunk ports, add them to a VLAN-Stack VLAN in the
following sequence starting in the CONFIGURATION mode:
Step Command Syntax Command Mode Purpose
1 interface vlan vlan-id CONFIGURATION Create a VLAN.
Enter VLAN mode.
2
3
4
vlan-stack compatible VLAN Designate the VLAN to be a stackable VLAN.
member interface VLAN Add the VLAN-Stack trunk port to the VLAN.
member interface VLAN Add the VLAN-Stack access port to the VLAN.
Use the show vlan command in the EXEC privilege mode to view the members of a VLAN-Stack
VLAN. Members of the VLAN-Stack VLAN are identified by M in the Q column.
Figure 142 show vlan Command Example
Force10#show vlan
Codes: * - Default VLAN, G - GVRP VLANs
NUM Status Q Ports
* 1 Active U Gi 13/0-5,18
2 Inactive
3 Inactive
4 Inactive
5 Inactive
6 Active M Po1(Gi 13/14-15)
M Gi 13/13
Force10#
Setting the protocol type for VLAN-Stack VLANs
In the packet header, the VLAN-stack protocol tag is added after the Destination Address and before the
VLAN ID (see Figure 138 on page 228).
In order to distinguish double-tagged traffic from other (single-tagged) traffic without having to parse the
Layer 2 headers (at non-VLAN-stacking aware switches, for example), it is necessary to carry the outer tag
with an Ethertype value other than the standard IEEE 802.1Q type (0x8100). Popular Ethertypes chosen
for this are 0x9100 (ad-hoc standard) and 0x88A8 (IEEE 802.1ad specified).
By default, FTOS sets the VLAN-stack protocol tag as 0x9100. To change the protocol number, use the
following command in the CONFIGURATION mode:
Command Syntax Command Mode Purpose
Members of a VLAN-Stack VLAN
vlan-stack protocol-type value CONFIGURATION Configure the protocol type to differentiate it from
other VLANs (default: 9100)
232 VLAN Stacking