Unanswered Question

hi! i've a few questions to verify about vss. currently we've 2x 6509e with 2x720 engine on each chassis. If i would to link up both chassis, can vss support more than 2x 720sup link up with 2 links on each pair? If i would to link up ony one sup in each chassis, what will happen to the unused sup?

can the module 5 - port 4 and 5 (both 10ge) be used as a etherchannel trunk port to link up both chassis? i remembered that i was prompted a msg for port 4 when i tried and the etherchannel is not successful.


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (2 ratings)
mmacdonald70 Sat, 11/14/2009 - 07:38
User Badges:

VSS does not yet support redundant supervisors. In fact adding a second supervisor will force the chassis to operate in non-vss mode.

VSS also requires the sup720-10GE

mmacdonald70 Sat, 11/14/2009 - 07:42
User Badges:

I missed the last paragraph.

In VSS mode you can use Ten5/4 and Ten5/5. It is recommended that you use ports on multiple cards. Preferably use one on a 6708 and another on a second 6708.

The error message that you got when you tried to add the ports to the Port Channel was most likely because the Portchannel and the Interfaces were in different modes (L3 and L2). Make sure that you change the ports to L2:

interface range ten5/4 - 5



Reza Sharifi Sat, 11/14/2009 - 09:49
User Badges:
  • Super Bronze, 10000 points or more
  • Cisco Designated VIP,

    2017 LAN

Hi David,

In addition to what Matt mentioned above,

VSS in general is very particular about the type and version of software and hardware you use.

1-Make sure you have the same exact IOS installed on both Sups. (The latest version on CCO is SXI3).

2-Make sure you have the same exact Sups installed in both switches. For example, if you have PFC-3C in one Sup; make sure you have the same one in the other Sup.

3-Be aware that you can not use the 4 port 10Gig module for your VSL link; however 8 port and 16 port modules are supported. You can use the 10Gig ports on the Sup or a combination of Sup and module.

4-Be aware that no POE modules are currently supported in VSS.

Please refer to this documentation on upgrading your switches to VSS.


Good luck



This Discussion