Vsan Trunking Mismatches; Vsan Trunking Protocol - Cisco AJ732A - MDS 9134 Fabric Switch Configuration Manual

Information About VSAN Trunking
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VSAN Trunking Mismatches

If you misconfigure VSAN configurations across E ports, issues can occur such as the merging of traffic
in two VSANs (causing both VSANs to mismatch). The VSAN trunking protocol validates the VSAN
interfaces at both ends of an ISL to avoid merging VSANs (see
Figure 35-2
In this example, the trunking protocol detects potential VSAN merging and isolates the ports involved.
The trunking protocol cannot detect merging of VSANs when a third-party switch is placed in between
two Cisco Nexus 5000 Series switches (see
Figure 35-3
Switch 1
VSAN 2 and VSAN 3 are effectively merged with overlapping entries in the name server and the zone
applications. The Cisco MDS 9000 Fabric Manager helps detect such topologies.

VSAN Trunking Protocol

The trunking protocol is important for E-port and TE-port operations. It supports the following
capabilities:
•
•
•
By default, the VSAN trunking protocol is enabled. If the trunking protocol is disabled on a switch, no
port on that switch can apply new trunk configurations. Existing trunk configurations are not affected:
the TE port continues to function in trunk mode, but only supports traffic in VSANs that it negotiated
with previously (when the trunking protocol was enabled). Other switches that are directly connected to
this switch are similarly affected on the connected interfaces. If you need to merge traffic from different
port VSANs across a nontrunking ISL, disable the trunking protocol.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
35-2
VSAN Mismatch
Switch 1
Third-Party Switch VSAN Mismatch
Third-party switches
VSAN 2
E port
Switch 2
Dynamic negotiation of operational trunk mode.
Selection of a common set of trunk-allowed VSANs.
Detection of a VSAN mismatch across an ISL.
Isolated
E port
VSAN 2
VSAN mismatch
Figure 35-3).
VSAN 3
E port
Switch 3
Chapter 35 Configuring VSAN Trunking
Figure 35-2).
Switch 2
E port
VSAN 3
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