Vlan-Trunking - Supermicro SSE-G2252 User Manual

vlan-trunking

This command allows unknown VLAN groups to pass through the specified interface.
Use the no form to disable this feature.
Syntax
[no] vlan-trunking
Default Setting
Disabled
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• Use this command to configure a tunnel across one or more intermediate switches
which pass traffic for VLAN groups to which they do not belong.
The following figure shows VLANs 1 and 2 configured on switches A and B, with VLAN
trunking being used to pass traffic for these VLAN groups across switches C, D and E.
Without VLAN trunking, you would have to configure VLANs 1 and 2 on all intermediate
switches – C, D and E; otherwise these switches would drop any frames with unknown
VLAN group tags. However, by enabling VLAN trunking on the intermediate switch ports
along the path connecting VLANs 1 and 2, you only need to create these VLAN groups
in switches A and B. Switches C, D and E automatically allow frames with VLAN group
tags 1 and 2 (groups that are unknown to those switches) to pass through their VLAN
trunking ports.
• VLAN trunking is mutually exclusive with the "access" switchport mode (see the
switchport mode
interface cannot be set to access mode, and vice versa.
• To prevent loops from forming in the spanning tree, all unknown VLANs will be
bound to a single instance (either STP/RSTP or an MSTP instance, depending on
the selected STA mode).
Figure 35-1. VLANs 1 and 2 Configured
command). If VLAN trunking is enabled on an interface, then that
35-17
Chapter 35: VLAN Commands