Cisco AP776A - Nexus Converged Network Switch 5020 Configuration Manual page 450

Configuring Trunk Mode and VSAN List
D r a f t Ve r s i o n 3 - 0 3 D e c 2 0 0 8 - C i s c o C o n f i d e n t i a l
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 Figure
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
For all F, N, and NP ports, the default VF_ID is 1 when there is no VF_ID configured. The trunk-allowed
VF_ID list on a port is same as the list of trunk-allowed VSANs. VF_ID 4094 is called the control VF_ID
and it is used to define the list of trunk-allowed VF-IDs when trunking is enabled on the link.
If F port trunking and channeling is enabled, or if switchport trunk mode on is configured in npv mode
for any interface, or if NP PortChannel is configured, the VSAN and VF-ID ranges available for
configuration are as follows:
Table 16-3
VSAN or VF-ID
000h
001h(1) to EFFh(3839)
F00h(3840) to FEEh(4078)
FEFh(4079)
FF0h(4080) to FFEh(4094)
FFFh
If the VF_ID of the F port and the N port do not match, then no tagged frames can be exchanged.
Note
Cisco MDS 9000 Family CLI Configuration Guide
16-10
16-5, switch 1 has VSANs 1 through 5, switch 2 has VSANs 1 through 3, and switch 3 has
VSAN and VF-ID Reservations
Figure 16-5.
Description
Cannot be used as Virtual Fabric Identifier
This VSAN range is available for user configuration
Reserved VSANs and they are not available for user
configuration.
EVFP isolated VSAN
Used for vendor-specific VSANs
Cannot be used as Virtual Fabric Identifier
OL-18084-01, Cisco MDS NX-OS Release 4.x
Chapter 16 Configuring Trunking