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Nexus 7000 with Fabric Extenders Nexus 2000

happyatuni
Level 1
Level 1

Dear all,

I have been tasked to replace the existing Cat 6500 and 3750 switches by Nexus 7000 and Nexus 2000.

I was told initially my boss plans to get 2 x Nexus 7000 and then eventually blow up to 4 x Nexus 7000s.

For Nexus, is there a list of tasks / points that i need to consider for building the initial design?

Can i just link the Nexus 7000 like the following?

              N7k-A    =========   N7k-B

                  |                                   |           

              lots of N2ks               lots of N2ks

Any pointers would be greatly appreciated.

Cheers,

Hunt

13 Replies 13

Marvin Rhoads
Hall of Fame
Hall of Fame

Wow that's a really big topic.

Rather than shoot in the dark with one of many possible answers, I'd suggest you first read the Smart Business Architecture Data Center Design Overview found here. It plus the "LAN and Data Center Consolidated Core Using Cisco Nexus 7000 Deployment Guide" on that same page will give you a lot of excellent information. Once you get familiar with the overall options, you might want to drill down into the VPC design guide here.

Those will all give you more context to perhaps frame any additional more specific questions.

Hope this helps.

Leo Laohoo
Hall of Fame
Hall of Fame

Uh-oh ... you're about to head into trouble.

The Nexus 7K, if you have Sup2, can only support up to 45 Nexus 2000 FEX.  How many is "lots of 2K"?

In regards to redundancy, the most financially efficient method is to get a single chassis, put two Supervisor cards, load N+1 FAB and line cards instead of purchasing two identical systems.

Here's my recommendation:  Your organization must probably have deeeeeeeeeeeeeeeeeep pockets if you are going down the Nexus 7K route.  Contact your nearest Cisco office and engage Cisco Professional Services.  Before the end of the week is over, you'll be getting alot of calls.

Sorry, may i ask what is FAB? And what do you meant by N+1 FAB?

http://Sorry, may i ask what is FAB? And what do you meant by N+1 FAB?

FAB is Nexus 7's switch FABric card.  The FAB controls the backplane speed of each slot of a Nexus chassis.  This is the speed of how fast each slot pushes traffic.

The FAB is upgradable and depends on your speed.  Each Nexus 7 can support to up to 5 FABs but, in reality, why waste money and buying 5 when, in worst cases, you can operate with just two and a third one as spare (hence the term "N+1"),

There are two models of the FAB:  FAB-1 and FAB-2.  FAB-1 can support 46 Gbps backplane (per slot) while FAB-2 can support up to 110 Gbps backplane (per slot).

For example, if you have a Nexus 7 and you want inter-link to a second Nexus 7 via 100 Gbps.  Let's say you have the money so you want two 100 Gbps and you want to use N7K-M202CF.  So you'll just need two FAB-2 (2 x 110 Gbps = 220 Gbps) and have one for spare (in case one of them fails).  In this scenario, your Nexus chassis can push two 100 Gbps NON-BLOCKING or wire speed. 

Remember that the FAB cards operate in per-slot speed.  This means that if you have, say four N7K-M202CF, then you will just need only TWO FAB cards minimum.

There are some Nexus 7K line card which may require up to four FAB-2 (excluding redundant) in order to push at wire speed. 

Hey Hunt,

Are you in Australia???

Yea I am.  Are you in Australia too?

Canberra, ACT.

I did a bit of reading and get a bit more confused:

1.  You mentioned each N7k can supports up to 45 Nexus 2000, is that 45 in total for the entire vPC? Or is it 45 Nexus 2000 x 2 = 90 Nexus 2000... as i would also imagine that i would need to dual home each Nexus 2000 to each of vPC peer (Nexus 7000)

2.  So is it normal for each Nexus 7k to have 2 x FAB cards each (for peer link), and can have a mixture of M1 or F1 cards for downstream vPCs?

3.  What is FabricPath?

I'm from Sydney, NSW 

1.  You mentioned each N7k can supports up to 45 Nexus 2000, is that 45 in total for the entire vPC? Or is it 45 Nexus 2000 x 2 = 90 Nexus 2000... as i would also imagine that i would need to dual home each Nexus 2000 to each of vPC peer (Nexus 7000)

Let's say you have a Nexus 7K with two Sup2 cards (one for redundancy).  Then you can have a maximum of 45 Nexus 2K/B22 FEX downstream.

What alot of people have done is to use Nexus 5K or Nexus 6K and connect the FEX to these because it's cheaper to get Nexus 5K/6K if you need to add more FEX. 

Nexus 5K can support 24 Nexus 2K in Layer 2 or 12 Nexus 2K in Layer 3. 

2.  So is it normal for each Nexus 7k to have 2 x FAB cards each (for peer link), and can have a mixture of M1 or F1 cards for downstream vPCs?

First of, M1/M2/F1 cards can co-exist in the same vDC.  Regular F2 card CANNOT co-exist with M1/M2/F1 card in the same vDC.  The newly released F2e card CURRENTLY cannot co-exist with M1/M2/F1 card in the same vDC.  But the next Nexus 7K firmware will lift this restriction on the F2e.

Regarding the FAB-2 cards, let me give you an example ... Let's say you have three N7K-F132XP card.  Now this card has a backplane speed of 230 Gbps.  Now a FAB-2 card can support up to 110 Gbps per slot.

So the question is:  How many FAB-2 cards do you require?

The answer is a minimum of two (2) and if you need redundancy, then three.   Two cards can allow the card to push up to 220 Gbps for all three cards.

Does this make any sense?

Thanks, it does make a lot more sense now 

Just thinking instead of having the downstreams as Nexus 2k, can i put a load of Nexus 1000V at the bottom and have them cross-connect to both Nexus 7k?

As for Nexus 1000V, is there any limits on it (i.e. how many VM hosts i can put on them?)

The 1000V is software only.

Okay, but how is the Nexus 1000V link up to the rest of the Nexus infrastructure?

For Agility, flexibility, and simplicity at scale Simplify your data center operations with Cisco Nexus 2000 Series Fabric Extenders. As part of the Cisco Data Center Networking portfolio, they integrate into existing network infrastructures as well as Cisco Application Centric Infrastructure (Cisco ACI). These fabric extenders offer a flexible solution to add access port connectivity to your data center network.

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