Ask The Expert: Nexus 5000 and 2000

ciscomoderator · ‎02-24-2012

With Lucien Avramov

Welcome to the Cisco Support Community Ask the Expert conversation. Get an update on Nexus 5000 and 2000 from Lucien Avramov. Lucien is a technical marketing engineer in the Server Access Virtualization Business Unit at Cisco, where he supports the Cisco Nexus 5000, 3000 and 2000 Series. He was previously a customer support engineer and Technical Leader in the Cisco Technical Assistance Center. He holds a bachelor's degree in general engineering and a master's degree in computer science from Ecole des Mines d'Ales as well as the following certifications: CCIE #19945 in Routing and Switching, CCDP, DCNIS, and VCP #66183.

Remember to use the rating system to let Lucien know if you have received an adequate response.

Lucien 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 Data Center sub-community discussion forum shortly after the event. This event lasts through March 9 , 2012. Visit this forum often to view responses to your questions and the questions of other community members.

Gustavo Hernandez · ‎02-28-2012

Hello Lucien,

Nice to see you again in the Ask the Experts. Is there a compatability table/matrix somewhere posted between Nexus products? I want to know in particular if the Nexus 2248TP GE is compatible with SFP-10G-SR?

Thank you.

Lisa

Lucien Avramov · ‎02-29-2012

Thank you for your question.

2248TP-GE is compatible with SFP-10G-SR for the 10GE uplinks.

When you use transceivers such as SFP-10G-SR or the FET ( FET-10G) , it's important to have the same transceiver on N5K as well as the N2K port.

You can find the compatibility information on cisco.com website:

http://www.cisco.com/en/US/products/hw/modules/ps5455/products_device_support_tables_list.html

You can either bookmark this link, or use a search engine with '

cisco sfp compatibility matrix' keywords.

Please let me know if you have any other questions.

rammuthaiya · ‎02-29-2012

Hi,

Please let know the best practice for connecting the server to Nexus 2000 and from Nexus 2000 to Nexus 5000.

This will enable me to do desing of our customers.

Ram

Lucien Avramov · ‎03-01-2012

If you have 5500 Nexus running 5.1.3.x version of code and above, the best practice is to use eVPC technology : this allows you to dual home your Nexus 2000 to a pair of Nexus 5500 regardless if you have single homed or dual homed (with port-channel) servers.

You can take a look regarding eVPC at:

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/layer2/513_n1_1/b_Cisco_n5k_layer2_config_gd_rel_513_N1_1_chapter_01010.html

Otherwise, the design is with:

-for dual attached server with a port-channel or FCOE with SAN A / SAN B : nexus 2000 directly attached to a nexus 5000 (no dual homing)

-dual homed nexus 2000 to each Nexus 5000 when you have single homed servers or no need for port-channeling.

Here is a design guide for that:

Data Center Aggregation Layer Design and Configuration with Cisco Nexus Switches and Virtual PortChannels

More information in general can be found at www.cisco.com/go/nexus5000 section design and section white paper

alanjbrown · ‎03-01-2012

Lucien,

We are looking to perform a two step Nexus 5000 upgrade as follows:

Stage 1: Non-ISSU

4.1(3)N2(1a) to 5.0(3)N2(2b)

Stage 2: ISSU

5.0(3)N2(2b) to 5.1(3)N1(1a)

We have a pair of N5K-C5020P-BF and N2K-C2148T-1GE in a vPC configuration (vPC-Peered Dual-Supervisor Virtual Modular System Dual-Homed FEXs )

I'm not quite sure about the upgrade process:

Stage 1: Non-ISSU

1) Install all on primary switch

2) Reload fex from secondary

3) Reload secondary switch after saving boot statements

Power cycle both 5020 for Power sequencer upgrade.

Stage 2: ISSU

1) Install all Primary

2) Install all Secondary

I have obviously simplified the process but have I got the basic steps correct.

Al

Bob Rizzo · ‎03-02-2012

I'm trying to figure out how to forward the udp broadcasts from my vpn phones coming in a one vlan destine for the UC vlan? Problem is our VPN phones work great connected to the ASA however when we push firmware to them they fail. In looking at the logs on the firewall everything seems to be passing but it seems that the phone is sending a udp broadcast and the UC servers are on a different vlan? We are using a Nexus 5548P with the L3 card and 2248's for the servers.

Thanks

Lucien Avramov · ‎03-05-2012

You can use the command

ip directed-broadcast under L3 interfaces or SVI's

You can take a look at:

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/unicast/5_0_3_N1_1/l3_ip.html

Lucien Avramov · ‎03-05-2012

Great steps, I'd upgrade with a small change for Stage 1)

Stage 1)

a) Install all on the primary

b) Power Cycle Manually Primary

c) Install all on the Secondary

d) Power Cycle Manually Secondary

(no need to reload the Nexus 2000, they will reload automatically initiated by the Nexus 5000 upgrade completion)

Stage 2) as you suggested

5.0(3)N2(2b) release notes:

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/release/notes/Rel_5_0_3_N2_1/Nexus5000_Release_Notes_5_0_3_N2.html

5.1(3)N1(1a) release notes with ISSU (please read the limitations section):

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/release/notes/Rel_5_1_3_N1_1/Nexus5000_Release_Notes_5_1_3_N1.html#wp348065

Just as an FYI, we upgraded the power sequencer in 4.2.(1)N1 version so any upgrade from an earlier version would undergo the power-sequencer upgrade. In your show version, it should show 1.2 version for the power sequencer once upgraded.

Also please note, that if you were to use the boot strings in step 1) instead of the install all command, it would *not* have upgraded your power sequencer.

Finally, you can take a look at a typical upgrade video for Nexus 5000 / 2000 here:

https://supportforums.cisco.com/videos/1206

Diana Mascarenhas · ‎03-07-2012

Hi Lucien,

As I mentioned earlier I do not see any latency in the ping response from the first pair of switches which is not cross connected(Connected as regular port channels), but I see the latency in the secondpair which are cross connected via VPC with 2 roots in the spanning tree. Should I give up the idea of using VPC and use regular ports channels as in the first pair.

Lucien Avramov · ‎03-07-2012

Let's please move to a recommended design first and then we can

investigate this further. You don't have a proper vPC design in your

scenario, on the pair of Nexus switches I pointed out.

Diana Mascarenhas · ‎03-05-2012

Hi Lucien,

I have 2 pair of Nexus switches in my setup as follows

The first pair connection as below

==========================

Nexus 1 (configured with vpc 1)----- 2 connections------ 6500 catalyst sw1(po 9)

Nexus 2 (configured with vpc 1) ----- 2 connections------ 6500 catalyst sw2 (po9)

po2 on nexus pair for vpc peer link

Spanning tree on Nexus 1

po1 root fwd1 p2p peer stp

po2 desg fwd 1 vpc peer link

Spanning tree on Nexus 2

po1 altn blk1 p2p peer stp

po2 root fwd1 vpc peer link

The second pair connection

=====================

Nexus3 (configured with vpc 20 ) ------ 1 connection ------- 6500 catalyst sw1 (po20)

(configured with vpc 30) ------- 1 connection ------- 6500 catalyst sw2 (po30)

Nexus4 (configured with vpc 20) ----- 1connection ---- 6500 catalyst sw1 (po20)(stp guard root)

(configured with vpc 30) ----- 1 connection ----6500 catalyst sw2 (po30)(stp guard root)

po1 on nexus pair for vpc peer link

Spanning tree on Nexus 3

po1 desg fwd1 vpc peer link

po20 root fwd1 p2p peer stp

po30 altn blk1 p2p peer stp

Spanning tree on Nexus 4

po1 root fwd1 vpc peer link

po20 root fwd 1 p2p peer stp

po30 altn blk1 p2p peer stp

Problem Observed : High Ping response

Source server on 1st pair of switches ; Destination server on 2nd pair of switches

Ping response from 1st pair of switches to destination server : normal (between 1 to 3 ms)

Ping response fron 2nd pair of switches to source server : (jumping from 3ms to 100+ ms).

There is no errors or packet drops on any of the above ports, I cannot understand why the ping response is high for connections from second pair.

Lucien Avramov · ‎03-05-2012

I would like to see your first Nexus Pair cross-connected to your 6500 catalyst chassis, in order to use vPC.

Otherwise you may use regular port-channels.

Could you make this design change and look again at your ping times?

Diana Mascarenhas · ‎03-05-2012

Hi,

I cannot change the design in the first pair of Nexus as it is in production. I am aware that using vpc serves no purpose there as the behaviour is similar to port channels & anyway I am not facing high respone time issue on those switches.

The high response time is on the second pair cross connected via vpc to 6500 catalyst. I can see two root paths in the Spanning tree output, is that behaviour normal or it is the cause of latency ?

Lucien Avramov · ‎03-06-2012

You are creating peer-traffic using the peer-keepalive link with this design actually, therefore I suggested the change to make it more predictable and reduce the peer-link traffic between the switches.