Cisco Cisco Catalyst 6500 Series VSSE 720 with 10GE uplinks Information Guide
Q&A
© 2009 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
Page 6 of 6
Q.
What happens if all VSL connections between the virtual switch members are lost?
A.
VSLs can be configured with up to eight links between the two switches across any combination of line cards or
supervisor ports to provide a high level of redundancy. If for some rare reason all VSL connections are lost
between the virtual switch members leaving both the virtual switch members up, the VSS will transition to the
dual active recovery mode.
The dual active state is detected rapidly (subsecond) by any of the following three methods:
●
Enhancement to PAgP used in MEC with connecting Cisco switches
●
L3 Bidirectional Forwarding Detection (BFD) configuration on a directly connected link (besides VSL)
between virtual switch members or through an L2 link through an access layer switch
●
L2 Fast-Hello Dual-Active Detection configuration on a directly connected link (besides VSL) between virtual
switch members (supported with 12.2(33)SXI)
In the dual active recovery mode, all interfaces except the VSL interfaces are in an operationally shut down state
in the formerly active virtual switch member. The new active virtual switch continues to forward traffic on all links.
in the formerly active virtual switch member. The new active virtual switch continues to forward traffic on all links.
Q.
How do the integrated service modules appear in a VSS environment?
A.
The integrated service modules in a VSS environment appear similar to how they would in a standalone
environment. For instance, two separate ACE modules in a standalone environment would continue to appear
and operate as two separate ACE modules in a VSS environment.
Q.
How does the Virtual Switching System 1440 operate in a server virtualization environment?
A.
VSS greatly aids in higher bandwidth utilization, scaling (via elimination of reliance on Spanning-tree protocol)
and availability of a virtualized server environment. For instance, dual-homed VMware ESX servers can operate
in an Active-Active (send and receive on all links) state enabling them to increase Virtual Machine (VM),
VMotion
®
and IP Storage performance.
Q.
Is VSS a validated Cisco design? When will the design guides be available for VSS?
A.
Yes, VSS is a Cisco validated design (CVD). Cisco SRND for both Campus and Data Center networks will be
available in CY’09.
Q.
Is VSS Cisco Safe Harbor program tested and certified?
A.
Yes, VSS is Safe Harbor program tested and certified. Please refer to the link below to stay current with safe
harbor testing updates.
http://www.cisco.com/en/US/netsol/ns504/networking_solutions_program_category_home.html
Printed in USA
C67-423240-05 08/09