Showing results for 
Search instead for 
Did you mean: 
Join Customer Connection to register!
Community Manager

Facebook Forum - Data Center Switching: Cisco Nexus Switches

Live chat with Cisco expert, Lucien Avramov on Cisco Nexus Switches

May 17th, 2012

Facebook_Forum_May 2012 - Data Center Switching.png

Lucien is a customer support engineer at the Cisco Technical Assistance Center. He currently works in the data center switching team supporting customers on the Cisco Nexus 5000 and 2000. He was previously a technical leader within the network management team. Lucien holds a bachelor's degree in general engineering and a master's degree in  computer science from Ecole des Mines d'Ales. He also holds the  following certifications: CCIE #19945 in Routing and Switching, CCDP, DCNIS, and VCP #66183

What is Facebook Forum?

Facebook forums are online conversations, held at a pre-arranged time on our Facebook page. It gives you an opportunity to interact with a live Cisco expert and get more information about a particular technology, service or product.


How do I participate?

On the day of the event, go to our Facebook page


To RSVP Click Here

Like us on Facebook   

Community Manager

Archive of the forum.            

Can you give an introduction to the Nexus 2000/5000?

Nexus 5000 and 2000 are part of our data center switching products. They are ideal for enterprise-class data center server access layer and smaller-scale, midmarket data center aggregation deployments. They can be deployed across a diverse set of traditional, virtualized, unified, and high-performance computing (HPC) environments. You can find all the cisco related documentation

I will soon be installing the Layer 3 license (LAN1) on our 5548 chassis - do I also need to install the BASE that came with the L3 daughter card? Is there an issue if it is done the other way around i.e. we install LAN and then BASE? If it does occur should we remove LAN1K9, install BAS1K9 and then install LAN1K9 again? It seems like its something likely to happen with the size of 5500 fleet we will deploy. Thanks in advance.

If you have LAN then please install BASE first, then proceed with installing LAN. And, yes, actually we need to install the BASE first then the LAN. In case you have the LAN already installed, you may use the CLI command clear license license_file.lic and remove the LAN, then proceed with installing BASE *then* LAN.

What SFPs can I use with Nexus switches? Can you address that?

You can use 1 GB or 10 GB SFPs. We have a compatibility matrix for each that lists the part-numbers and type that are supported. For 1 GB:, For the 10 GB:

Can I use ethanalyzer to sniff traffic between 2 hosts?

Ethanalyzer is a tool to capture packets going to the control-plane on N5K (CPU). To sniff traffic between hosts, you can use SPAN and configure a monitoring session.
Here is more information about SPAN:
And here is more information about Ethanalyzer:

Another white paper regarding Ethanlyzer:

Can another switch ever be connected to a 2248 FEX?

Yes you can connect a switch to a 2248 FEX. What you have to be careful is in that case to not introduce a loop in the network as there is no spanning-tree running on the FEX. So if you're purpose is to add a switch to connect hosts that should be okay, however if you introduce a loop, it will take your network down. To get the port up on the FEX please use spanning-tree bpdufiler command. It is not best practice and we don't recommend it, however you can achieve this.

Where we can find a video demonstration about how we implement "switch nexus 1000v" in data centers?

There are videos and also quite lots of documentation regarding nexus 1000v here:

Where can we find videos on Nexus?

Regarding Nexus videos, there is a great place here:

What are the Cisco best practices/guidelines to configure a 2248 for L3 switching that is connected to a 7010?? And are there configuration examples anywhere?

You can use the 2248 in L3 mode, meaning: provide an IP address on the FEX port when you connect it to the 7000 series. It's no really different than an L3 port as far as best practice. Here is the configuration to it:

Some more information about FEX and N7K for L3: we have option on 7k to configure fex port in L3 mode. In addition you can terminate fex l2 port with SVI, same as 5k. In either of those cases, you cant use FEX for dynamic routing peering which is a big difference with regular L3 ports on N7K linecards.

What is Enhanced vPC?

The enhanced virtual port channel (vPC) feature allows the dual homed connection of a host to two fabric extenders (FEXs) or a dual homed connection of a FEX to two switches. The great thing is that the FEX is FCOE aware, so with eVPC, you can still have your SAN_A and SAN_B taking different physical paths, while providing the active-active redundancy to your hosts connected to the Nexus 2k/5k switches. Take a look here for the diagram. It is a feature we have introduced in 5.1.3 software release :

Is there MPLS support on Nexus switches?

There is MPLS support on Nexus. This is possible on our Nexus 7000 product family. You can use the M series line cards.

Here are more details about it:

How many VDC does N7k Supports?

You have up to 4 VDC today. This is documented in the great documentation limits guide :

Also, in case you would like to learn more about VDC here is a good white paper:

What discovery process/criteria can be used evaluate an organizations current network design in order to implement a Cisco preferred OTV deployment model?

It's important to evaluate types of apps needing L2, availability of unicast or multicast IP connectivity between sites, # of VLANs that need to be extended and # of MACs.

Where can we find videos on Nexus?

Regarding Nexus videos, there is a great place here:

Nexus 5548UP and 5596UP has GEM slots that can hold a 16 port GEM module. Is 4 port 40Gig module for Nexus 5500 planned? This will be very great for uplinks to nexus 7000 40 gig module.

Yes, we have a great plan to support QSFP with GEM modules. Stay tuned!

How does the loop prevention mechanism works when you configure VPC between three switches?

Check here for more information:

Where can I go to learn more about Nexus and DataCenter products in general?

To learn more about Nexus, Data Center products and more in general about any cisco product, the following pages are very useful (configuration guides, white papers..),,

We also have a forum available for anyone to use (you can create your account): Regarding Nexus, you can find many questions here: And finally there are videos on demand (youtube format) I have posted here for the Nexus:
For example, here is a video about how to configure vPC (virtual port-channel):


To visit the actual forum that took place on Facebook visit here: