Which of the following methods is best for redundancy in a Cisco 6500?

  1. Two Cisco 6500 chassis each with a single Sup720 and other modules.
  2. One Cisco 6500 chassis with two Sup720 modules and two of each of the other modules.
  • 1
    Redundancy in what sense? – joeqwerty Mar 28 '11 at 11:39

Depending on what Sup720 you have (or plan to buy) you could consider a 3rd option. With the VSS-720-10G Supervisor you can "cluster" two 6500 boxes to appear as one single entity with very fast failover between the two, you need decent 10gig line cards for this though, x6708 typically. Each chassis can have one or two supervisors for redundancy.


There is quite a long list of pros and cons for this type of setup, best is to google and speak to your Cisco sales rep about the options.

Also worth keeping in mind that the Nexus is the next generation switch for datacentre deployments, if you don't need the services offered on the 6500 (6500 = services and Nexus = performance) you might want to consider Nexus instead. On high density 10GE the Nexus is a lot cheaper.

  • 1
    vss is such a great thing, answer needed an upvote ! – petrus Mar 28 '11 at 17:20
  • Thanks for your good advice. So to be clear you would sugest, having two chassis each with VSS-720-10G for clustering. Sounds good, but very expensive. I was getting the SUP720 without VSS. I have planned to purchase x6708 modules. Think I can still do failover without the VSS support, is that correct? – Stokie Mike Mar 29 '11 at 15:26
  • You can still use other common (but slower) technologies like HSRP for failover of layer3 interfaces and spanning-tree will do layer 2 etc. Works fine but not as scalable and quick to converge. – HampusLi Mar 30 '11 at 8:27

This needs more information, however I would be inclined to go for 1, Two Cisco 6500 chassis each with a single Sup720 and other modules.

My reasons being, you can then locate the devices in separate locations, should one location "go dark", the other should continue to run with the separate hardware.

  • Thanks for your information. I will be having them on the same Data Centre location but on separate UPS devices, breakers and power supply. – Stokie Mike Mar 28 '11 at 16:34
  • I can provide more information if required for your opinion. Thanks – Stokie Mike Mar 29 '11 at 15:27
  • @Stokie Mike, In my opinion having 2 chasis is going to give you the best resilience. Even in the same DC, from the information you have given they will be on seperate UPS's this would guard against a single UPS failure (unlikely but call me paranoid) – Oneiroi Mar 30 '11 at 10:30

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