Datacenter evolution: N7k or C6500

[parisdooz12]

Hi,

I curretnly study how to make our datacenters evoluate.

For the physical physical architecture:

- We have 2 datacenters, L2 interconnected in 10gbps.

- On each datacenter, 2 x C6500 act as core and distribution in the same time.

- The access layer consists in C3750G, connected to core chassis with 3x1Gbps etherchannels.

- No blade servers rack for the moment.

For the logical aspect:

- L2: we use STP extended on the 2 DC

- L3: Core are directly connected to the MPLS cloud. We use VRFs.

The next server evolution should be to replace standalone servers by blade, connected with 10Gbps.

I have hesitation about how to upgrade the current design, and I am not sure about the + and - of the 2 one (apart that Nexus need investments)

1) Keep the C6500 and:

- add 10Gbps cards on the C6500 (16 ports cards)

- use VSS on both site to simplify STP design (even if we had no problem with it up to now)

2) replace C6500 by Nexus7K for better flexibility with 10Gbps

3) in option, add a N5K distribution layer wich would simplify cabling, and would permit potential evolution to FCoE (in this solution, I would keep C6500 as core or evoluate to N7k).

What's your advices?

Thanks

P.

[Leo Laohoo · Accepted solution]

This is going to be a very heated topic.

Let's not talk about budget here because it could get very murky.

The 6500, either Sup720 or Sup2T (I'd still prefer the latter), is very good when you are aggregating a significant amount of 1 Gbps and a few 10 Gbps and a handful of 40 Gbps.

The Nexus family is very good when you want to consider a few 100 Gbps but a significant amount of 10 Gbps.  Nexus is also the way to go if you want to connect your Fibre Channel to a DC switch as Nexus will support 1-, 2-, 4- and 8Gbps FC.  

Nexus 7K can support 100 Gbps (two per line card), 40 Gbps (six per line card) and of course 10 Gbps (up to 48 per line card).

Very soon, the will be some service modules that will be introduced for the Nexus 7K.  They are WAAS, ASA and a NAM.

Will there be life with the 6500?  In some cases, yes.  It is still not clear if ALL the service modules for the 6500 will evolve  to the Nexus.  I believe the three modules I've just mentioned is to "test" the waters.  Once momentum has been achieved, the others might follow.

There are rumours abound that there could be a possibility of Nexus 2K that will support PoE.

Attached something for your perusal.

[parisdooz12]

Hi,

ok, thanks for the answer and the attached file, really usefull.

Following our needs, C6500 seems to be the best choice, as I think the max 10Gbps ports we will need on a chassis will be less than 20 (and we still need to keep 1gbps).

What other doubt I had was about VSS versus vPC: is one technology better than the other, or can we consider both having the same stability (I actually had doubt about VSS as I could see in the past some bugs that made me scared just the idea to use it on a datacenter! But it was 2 or 3 years ago, so...)

[Leo Laohoo]

Hard to tell.

VSS is here to stay.   Sup720 started the "concept" of VSS.  Alot of people loved the concept and started eating from Cisco's hand.

So VSS will be pushed "down" to the 4500R+E (Sup7E) and the 4500X.

vPC and VSS are similar but they serve their own purpose.

If you have the funds to purchase equipment, my money would be on the Nexus family.

Talk to your Cisco Sales Enginner/Account Manager and ask them about the soon-to-be-announced Nexus 6K. 

[parisdooz12]

Ok. Thanks for informations!

[Surya ARBY]

I don't like N7K; too many bugs and globally; poor feedbacks (also discussed this topic with various trainers).

2 years ago Gartner group sent to all major accounts (worldwide) on behalf of a big Cisco customers an inquiry around all these technical issues.

Right now I build my datacenters based on 5k/2k for L2 access / aggregation; and then I use catalyst "on-a-stick" for routing.

[parisdooz12]

Ok, thanks for your feedback. I plan to follow such a strategy. I plan to keep C6500 as a core chassis of my datacenter, then add a N5K layer.Our existing C3750G stacks will be migrated on N5K, then we will migrate C3750G to N2K next year.

[Leo Laohoo]

parisdooz12 wrote:
Ok, thanks for your feedback. I plan to follow such a strategy. I plan to keep C6500 as a core chassis of my datacenter, then add a N5K layer.Our existing C3750G stacks will be migrated on N5K, then we will migrate C3750G to N2K next year. 

Just don't be tempted to upgrade to a Sup2T. 

[parisdooz12]

No no, our Sup720 are widely enough! (hum ... by the way, is it a problem with Sup2T?)