Ask the Expert- Evolution of Data Center: From Classic Ethernet to VXLAN

Cisco Moderador · ‎05-14-2018

This topic is a chance to discuss more about the changes that the Data Center technology has gone through in order to meet business requirements and to learn more about the best practices and troubleshooting tips on Nexus. The session focus in all the latest features added to the Nexus 7000 and 9000, such as virtual Port Channel (vPC), FabricPath, VXLAN, and ACI, along with the best practices to implement and design them.

It covers single switches and large Layer 2 domains to Virtual eXtensible LAN (VXLAN) and Application Centric Infrastructure (ACI) advantages and improvements.

To participate in this event, please use the button below to ask your questions

Ask questions from Tuesday 15th to Friday 25th of May, 2018

Featured Expert

Tiago Silva is a Network Consulting Engineer with over 15 years of experience in the IT industry and currently works at Cisco’s Global Service Provider (GSP) in Montreal. Tiago has experience in several IT fields such as Transport Networks, Security, Wireless, and LAN/WAN. However, in the last years he has focused on Service Provider and Data Center technologies. He has worked at Embratel, Alstom, Capgemini, and Aimia (Aeroplan). Tiago holds a Bachelor’s degree in Information Technology and a Telecom technician degree. He also has several certifications: CCNA wireless, CCNA Security, CCDP, CCNP R&S, and a CCIE DC (#58005).

Tiago might not be able to answer each question due to the volume expected during this event. Remember that you can continue the conversation on the Contact Center Community

Find other events https://supportforums.cisco.com/t5/data-center/ct-p/4436-data-center

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Cisco Moderador · ‎05-16-2018

Hi Tiago

Thanks for your time yesterday and for sharing all your knowledge with us, it was a great session.

Please help to answer the following questions from the session:

Can you repeat which are the best practice in regards to where to connect the keep alive?Currently we passed one of ours through our core and it did have a major failure when one of our core switches randomly rebooted a few months ago. Now, we're trying to devise a better place to run the PK. What are your thoughts on using a crossover cable?

What if Peerlink fails, can peer keep alive carry STP, HSRP traffic? How long are we allowed to keep the PeerLink down?

When the peer-link goes down while the keep alive is up, doesn’t that prevent the CFS messages from being exchanged ( STP BPDU and HSRP hello)? This could cause issues

In our Datacenter we use VRF for multitenancy, what is the cutting edge advantage if we get it with VXLAN?

Is there any document to migrate classical Ethernet switches or VPC switches to VXLAN or ACI? Or one with best practices to accomplish this migration?

Is there a document that features a case in which we have a new deployment with ACI or VXLAN, are there any considerations that we need to take into account?

tiagosil · ‎05-18-2018

Hi everyone, I'll start answering the questions here:
Q: Can you repeat which are the best practice in regards to where to connect the keep alive?Currently we passed one of ours through our core and it did have a major failure when one of our core switches randomly rebooted a few months ago. Now, we're trying to devise a better place to run the PK. What are your thoughts on using a crossover cable?

A: Below you can see a table with the recommendation per platform. Where you see Direct Link would be similar to crossover cable (or fiber) between the devices

tiagosil · ‎05-18-2018

Q: What if Peerlink fails, can peer keep alive carry STP, HSRP traffic? How long are we allowed to keep the PeerLink down?

Q: When the peer-link goes down while the keep alive is up, doesn’t that prevent the CFS messages from being exchanged ( STP BPDU and HSRP hello)? This could cause issues.

A: If VPC Peer-Keepalive (PKL) link is still up and only Peer-Link (PL) is down, PKL will not pass any STP, HSRP, etc traffic on it. It serves only to see if the other peer is alive. The scenario during the issue will be:

- VPC PL is down (link loss)

- VPC PKL is up
- Status of other VPC peer is known (via PKL)

- Both peers Active

- Secondary VPC peer disables all VPCs (confirm role via "show vpc role")

- Traffic via VPC Primary

- Traffic from orphan devices connected to secondary peer will be blackholed.

tiagosil · ‎05-18-2018

Q: In our Datacenter we use VRF for multi-tenancy, what is the cutting edge advantage if we get it with VXLAN?

A: I would start saying that you won't be limited by your VLAN numbers anymore. Not sure about the size of your DC or how many Leaves (Access switches) you have but going to VXLAN you wouldn't need to extend the same VLAN to all switches. With this said, you would also reduce the consumption of MAC address table per leaf switch.

It would be easier to extend the same Layer 2 domain over multiple DCs for high availability / Disaster Recovery. A customer would also be able to extend his Layer 2 from his environment up to your DC or you could encapsulate the traffic directly form the host running Nexus 1000v, for example.

In summary: saves resources and increase possibilities :)

tiagosil · ‎05-18-2018

Q: Is there any document to migrate classical Ethernet switches or VPC switches to VXLAN or ACI? Or one with best practices to accomplish this migration?

Q: Is there a document that features a case in which we have a new deployment with ACI or VXLAN, are there any considerations that we need to take into account?

A: I always like to start with some presentations available on Cisco Live (www.ciscolive.com). They will give you a good/practical view of what to expect from the project:
BRKDCN-2404 - VXLAN Deployment Models - A practical perspective
BRKDCN-3378 - Building DataCenter Networks with VXLAN BGP-EVPN
BRKACI-2345 - Designing and Deploying ACI - Lessons From The Field
BRKACI-3101 - ACI Under the Hood - How Your Configuration is Deployed

After, you go through these documents:

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-737909.html

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-738503.html

thomaskelley1 · ‎05-22-2018

Weak presentation. Seems like just content from other presentations hurriedly assembled.

tiagosil · ‎05-22-2018

Hi Thomas,

I'm sorry it didn't fulfilled your expectations. Thanks for your feedback, it will certainly help preparing for other ones.

The idea was really to give an overview of all technologies. I'd be more than happy to help you with other with any topic that you'd like to know more in more details.

Hilda Arteaga · ‎05-22-2018

Hi @thomaskelley1 thanks for your feedback.

@tiagosil thanks for considering this comments into consideration.

Hilda Arteaga · ‎05-18-2018

Hi Tiago

Thanks for the awesome webcast!

Her are more questions from the audience:

Q: Do nx9k3 switches support anycast gateway functionality besides hsrp/vrrp?

Q: When the peer-link goes down while the keepalive is up doesn’t prevent the CFS messages from being exchanged ( STP BPDU and HSRP hello) which could break things?

Q: Can we run MACSec over one or more VXLAN's or must we run MACSec at the physical L2 port?

Q: What is significance of STP on the latest Data Center topologies?

Q: Is it recommended to use 9k/2k as leafs or just 9k's?

Q: What is difference between vpc and vpc+?

Q: Do you have any chart that addresses the comparison between all those protocols?

sboddy · ‎05-25-2018

Any plans to add OTV to the Nexus 9000 platforms?