Cisco Nexus 5000 Series Switch Fabric Manager Software Configuration Guide, NX-OS 4.0 (OL-16598-01, June 2008)

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Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 13 Configuring VSAN Trunking
Configuring VSAN Trunking
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 Figure 13-6, 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 Figure 13-6.
Figure 13-6 Default Allowed-Active VSAN Configuration
You can configure a selected set of VSANs (from the allowed-active list) to control access to the VSANs
specified in a trunking ISL.
Using Figure 13-6 as an example, you can configure the list of allowed VSANs on a per-interface basis
(see Figure 13-7). For example, if VSANs 2 and 4 are removed from the allowed VSAN list of ISLs
connecting to switch 1, the operational allowed list of VSANs for each ISL would be as follows:
• The ISL between switch 1 and switch 2 includes VSAN 1 and VSAN 3.
• The ISL between switch 2 and switch 3 includes VSAN 1 and VSAN 2.
• The ISL between switch 3 and switch 1 includes VSAN 1, 2, and 5.
Consequently, VSAN 2 can only be routed from switch 1 through switch 3 to switch 2.
V
SANs1, 2, and 3 are o
perational.
VSANs 1, 2, 4,
5areoperationa
l.
VSANs 1 and 2 are operational.
Switch 3
VSAN1
VSAN2
VSAN4
VSAN5
Switch 1
VSAN1
VSAN2
VSAN3
VSAN4
VSAN5
Switch 2
VSAN1
VSAN2
VSAN3
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