Data center redesign

[Zaaf Aba]

Hi all

I am trying to seek help in connecting two data centers which are appx 65km apart. For ease of explanation they will be refereed as SiteA and SiteB . Currently both sites are connected with two x 1gbps fiber links. One of 1gbps link at both end is connected to the top switch in the stack and the second link is connected to the bottom switch(non Cisco) in the stack at both sites. Historically Etherchannel was not established between stacks because of some issues and then never tried again. Hence one of the two links is not in use because of stp. Both DC are L2 connected and there are only half a dozen vlans at both sites and a dozen HyperV servers with multiple 1gbps RJ45 to the
It is now time to redesign, more vlans, DR, two x 10gbps cross site links, new switches/routers to connect SiteA and SiteB. As it is a live environment changes to existing infrastructure are not welcomed. Business is happy to redesign new data center LAN and WAN network to be ready for HyberV server and cross site link migration.

Please advise

- Which Cisco switches should be choose for both sites. I had a look at Cisco Nexus 3 and 5 series. We need 22 10gbps ports, 160 1gbps RJ45 ports. Preference is to have half of these of one switch and the remaining half on the other switch at SiteA and similar setup at SiteB
- Should we get total of four 24 port Nexus 3k or 5k switches with six Cisco Nexus 2000 Series Fabric Extenders or is there a better option?
- Should vPc be configured between all four Nexus 3k/5k switches? or vPC between two Nexus switches at SiteA and same at SiteB
- What is the best way to connect two x 10gbps cross data center links?

How can Cisco Application Centric Network (ACI) , Virtual Extensible LAN (VXLAN) help us?

Thanks a lot in advance. I am new to Nexus world

Regards

Zaaf

[Francesco Molino]

Hi

First of all, before choosing the Nexus model you want you need to decide if ACI will be something you're looking at. ACI is compatible with Nexus 9k.

VXLAN is a cool technology that allows you to extend your L2 over L3.

Some advantages of VXLAN:

- Remove flooding on L2

- Scalability: 16M different segment on the same network instead of 4096.

Here some videos and documentations to read before taking a decision:

- https://www.youtube.com/watch?v=ZvITtE-gQYg

- https://www.cisco.com/c/en/us/products/collateral/switches/nexus-7000-series-switches/fundamentals-of-vxlan.html

- https://www.cisco.com/c/dam/m/sl_si/events/2016/cisco_dan_inovativnih_resitev/pdf/cisco_day_slovenia_2016_vxlan_marian_klas_final.pdf  --> Design Guide

- https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/1-x/aci-fundamentals/b_ACI-Fundamentals/b_ACI-Fundamentals_chapter_010010.html --> VXLAN in ACI

After that, yes you can have NExus 3k, 5k and/or 9k with FEX (N2k). Just take a look on compatibility matrix to validate that FEX needed are compatible with your parent Nexus switches.

In terms of vPC (standard design):

- You will have a vPC Peer-Link between 2 Nexus on Site A and 2 Nexus on Site B

- You can interconnect them with a big port-channel (vPC) between these 4 Nexus switches.

But again, if you're going to use VXLAN, take a look on documentation I gave you previously as the design would be a little bit different.

Now, I understand that you're talking about DC then thinking about Nexus family switches. However, what are your requirements because you can also have Catalyst models that can fit in your environment.

Sorry if that doesn't answer exactly your questions but before moving forward with this or the other design, you need to be sure of what you want to achieve and what are your needs.

[Zaaf Aba]

Hi  Francesco

Thanks for your reply. I will go through the links provided.

The immediate requirement as this stage is to connect appx.

12 HyperV servers at SiteA and 12 HyperV server at SiteB with each having two x 10gbps fibre connection. Allowing vlan managed by Hyperv itself (some sort of SDN)

Then migrate appx 192 x 1gbps RJ45 ports at SiteA and similar number at SiteB. I came from CatOs , IOS catalyst background. Haven't worked on Nexus.

you are correct that I am thinking about Nexus because of Data centers. Can you please put some light on what can't be done if we use catalyst in our

Data centers?

Thanks

[Francesco Molino · Accepted solution]

Hi Zaaf,

When I asked about your needs, this more in terms of features. Then we can compare feature vs price and see which fits best.

However, based on the number of ports needed, Nexus will be a perfect fit with FEX as top of the rack switches.

In terms of Catalyst I was thinking about new platform Cat9k. But again, this choice will be based on real feature needed like (qos, security, bandwidth,.....)