ASK THE EXPERT - Nexus 5000 & 2000 series

[ciscomoderator]

with Lucien Avramov

Welcome to the Cisco Networking Professionals Ask the Expert conversation. This is an opportunity to learn how to troubleshoot Nexus 5000 & 2000 series with Lucien Avramov.  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.

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 Security discussion forums shortly after the event. This event lasts through March 11, 2011. Visit this forum often to view responses to your questions and the questions of other community members.

[Lucien Avramov]

Great questions. The FEX depend on the buffer of the 5k.

The 2148 has better buffer management from 4.2.1 code of NX-OS.

There is about up to 320/375 kb per 4 ports as buffer (shared buffer)

There is a cli command to use so one port can absorb more shared buffer from the 4 ports to absorb burst, that would be useful in isci for example for 2148:

N5k(config)# system qos

N5k(config-sys-qos)# no fex queue-limit

The default threshold works fine on 2248 and 2232.

You configure the QoS for 2248 from the N5K via the service
-policy.

[r.westman]

Hi,

We have a ESX-machine connected with a port-channel (LACP) to two 2248, each 2248 singled attached to a separate 5548. When we power down both 5548 and then turn on only one of the 5548, the ESX machine never comes online. The 5548 takes the primary role after reboot, the VPC goes up, the interface connected to the ESX machine goes active. And the LACP negotiation seems to be ok. But the ESX machine never answers any ping until the other 5548 is turned on and the peer-link is formed again. What can be wrong?

Regards

Interface Ethernet102/1/13 is up

  Channel group is 13 port channel is Po13

  PDUs sent: 63

  PDUs rcvd: 58

  Markers sent: 0

  Markers rcvd: 0

  Marker response sent: 0

  Marker response rcvd: 0

  Unknown packets rcvd: 0

  Illegal packets rcvd: 0

Lag Id: [ [(7f9b, 0-23-4-ee-be-14, 800d, 8000, 230d), (ffff, 0-1c-c4-d8-fd-66, 11, ff, 1)] ]

Operational as aggregated link since Fri Mar 11 14:03:38 2011

Local Port: Eth102/1/13   MAC Address= 0-5-73-c3-4b-fc

  System Identifier=0x8000,0-5-73-c3-4b-fc

  Port Identifier=0x8000,0x230d

  Operational key=32781

  LACP_Activity=active

  LACP_Timeout=Long Timeout (30s)

  Synchronization=IN_SYNC

  Collecting=true

  Distributing=true

Actor Admin State=(Ac-1:To-1:Ag-1:Sy-0:Co-0:Di-0:De-0:Ex-0)

Actor Oper State=(Ac-1:To-0:Ag-1:Sy-1:Co-1:Di-1:De-0:Ex-0)

Neighbor: 0/1

  MAC Address= 0-1c-c4-d8-fd-66

  System Identifier=0xffff,0-1c-c4-d8-fd-66

  Port Identifier=0xff,0x1

  Operational key=17

  LACP_Activity=active

  LACP_Timeout=Long Timeout (30s)

  Synchronization=IN_SYNC

  Collecting=true

  Distributing=true

Partner Admin State=(Ac-0:To-1:Ag-0:Sy-0:Co-0:Di-0:De-0:Ex-0)

Partner Oper State=(Ac-1:To-0:Ag-1:Sy-1:Co-1:Di-1:De-0:Ex-0)

[Lucien Avramov]

ESX nor ESXi support LACP. You can do a port-channel without lacp (channel-group mode on).

If you need LACP support you can use the Nexus 1000v on ESX.

[lnxnut.certeon]

Hello Lucien,

I have been working with ESX and ESXi for a couple of years and am now just getting into using the nexxus.

Is there a "trial" period that I can download and use it before I have to come up with a PO?

Thank you,

Rick

[Lucien Avramov]

Sure, you can try it for a 60 days period and download it from our website.