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S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
1-4
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 1 Configuring VSAN Trunking
Configuring VSAN Trunking
Tip
The preferred configuration on the Cisco Nexus 5000 Series switches is that one side of the trunk is set
to auto and the other is set to on.
Note
When connected to a third-party switch, the trunk mode configuration has no effect. The ISL is always
in a trunking disabled state.
Configuring Trunk Mode
To configure trunk mode, perform this task:
About Trunk-Allowed VSAN Lists
Each Fibre Channel interface has an associated trunk-allowed VSAN list. In TE-port mode, frames are
transmitted and received in one or more VSANs specified in this list. By default, the complete VSAN
range (1 through 4093) is included in the trunk-allowed list.
The common set of VSANs that are configured and active in the switch are included in the trunk-allowed
VSAN list for an interface, and they are called
allowed-active VSANs
. The trunking protocol uses the
list of allowed-active VSANs at the two ends of an ISL to determine the list of operational VSANs in
which traffic is allowed.
In
, switch 1 has VSANs 1 through 5, switch 2 has VSANs 1 through 3, and switch 3 has
VSANs 1, 2, 4, and 5 with a default configuration of trunk-allowed VSANs. All VSANs configured in
all three switches are allowed-active. However, only the common set of allowed-active VSANs at the
ends of the ISL become operational as shown in
Off
Auto, on, or off
No trunking (ISL)
E port
Auto
Auto
No trunking (ISL)
E port
Table 1-1
Trunk Mode Status Between Switches (continued)
Your Trunk Mode Configuration
Resulting State and Port Mode
Switch 1
Switch 2
Trunking State
Port Mode
Command
Purpose
Step 1
switch#
configuration terminal
Enters configuration mode.
Step 2
switch(config)#
interface
fc
slot/port
switch(config-if)#
Configures the specified interface.
Step 3
switch(config-if)#
switchport trunk mode on
Enables (default) the trunk mode for the
specified interface.
switch(config-if)#
switchport trunk mode off
Disables the trunk mode for the specified
interface.
switch(config-if)#
switchport trunk mode auto
Configures the trunk mode to
auto
mode, which
provides automatic sensing for the interface.