Ask the Expert: Troubleshooting Nexus 5000/2000 series switches

[ciscomoderator]

With Prashanth Krishnappa

Welcome to the Cisco Support Community Ask the Expert conversation. This is an opportunity to learn about how to troubleshoot the Nexus 5000/2000 series switches.

Prashanth Krishnappa is an escalation engineer for datacenter switching at the Cisco Technical Assistance Center in Research Triangle Park, North Carolina. His current responsibilities include escalations in which he troubleshoots complex issues related to the Cisco Catalyst, Nexus and MDS product lines as well as providing training and author documentation. He joined Cisco in 2000 as an engineer in the Technical Assistance Center. He holds a bachelor's degree in electronics and communication engineering from Bangalore University, India, and a master's degree in electrical engineering from Wichita State University, Kansas. He also holds CCIE certification (#18057).

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

Prashanth 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 June 29, 2012. Visit this forum often to view responses to your questions and the questions of other community members.

[samuelmendieta]

Hi Prashanth. A pleasure to greet, my name is Samuel. I am trying to set certain SNMP commands in the Nexus 7000 in our network, to monitor the computer for any problems and do not know where to configure them.

On a Cisco router I can configure it normally, but, in the Nexus does not.

The commands are as follows on a Cisco router:

access-list 80 permit xx.xx.xx.xx 0.0.0.255                                      

access-list 81 permit xx.xx.xx.xx 0.0.0.255                                        

snmp-server community bMc-pupl!c RO 80                                            

snmp-server community bMc-pr!V4t3 RW 81                                            

snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart  

snmp-server enable traps envmon fan shutdown supply temperature                    

snmp-server enable traps syslog                                                        

snmp-server host xx.xx.xx.xx bMc-pupl!c

¿As I can do the same in the NEXUS?

They help me with this problem please

thanks

[Prashanth Krishnappa]

Hi Samuel

This event is closed. But I will try to answer it. I do see an option for use-acl in my switch.

20-11-7010-N7k-Core-A(config)# snmp-server community public use-acl ?

  WORD  Acl name to filter snmp requests (Max Size 32)

Thanks

-Prashanth

[marc.russo]

Hi,

A quick question about port-channel load balancing algorithms on a Nexus 5020.  Can I change the algorithm on the fly without adverse affects?  I need to change from "source dest IP" to "source dest port" but I am worried about what happens to my port channels while I make this change.

Thanks

Marc

[Prashanth Krishnappa]

Hi Marc

This event is closed but I will try to answer your question. You can make load-balancing change with no impact

Thanks

-Prashanth

[mithun.ghosh]

hi ,

i have two Cisco Nexus  5k's in vpc and and cisco fex 2k and cisco 2960 switch as access layer in downstream.

configured vtp on both 5k's and whenever i am trying to add or delete vlan on N5K server switch the revision number does not increase and the vlans not propagating to the down stream switches.

can you please help me in this case

regards ,

Mithun ghosh

[gonzalo.diaz.meza]

Hi,

I am trying to configure FHRP with two Nexus 5K With no vPC in SVI's but i cant make one of them "passive". It seems to be an issue with incoming hellos because i have connected a 3750 to both of them in the same vlan and i have runn debugs. The test fails with VRRP in SVIs and HSRP in SVIs

This test is with only one 5k and a 3750 with HSRP

Run in N5K

interface Vlan1712

  no shutdown

  description LAN DMZ PrivateCORP

  ip address 10.208.204.2/24

  hsrp 111

    authentication text test

    preempt

    priority 150

    ip 10.208.204.1

N5K_Esperanza_1#

N5K_Esperanza_1#

N5K_Esperanza_1#

N5K_Esperanza_1# sh hsrp brief

                     P indicates configured to preempt.

                     |

Interface   Grp Prio P State    Active addr      Standby addr     Group addr

Vlan1712    111 150  P Active   local            unknown          10.208.204.1    (conf)

N5K_Esperanza_1#

Debug

N5K_Esperanza_1# 2013 Apr 25 21:14:14.812585 hsrp: Vlan1712[111/V4]: Hello out Active pri 150 ip 10.208.204.1

2013 Apr 25 21:14:14.812605 hsrp: Vlan1712[111/V4]: hel 3 hol 10 auth test

2013 Apr 25 21:14:17.812686 hsrp: Vlan1712[111/V4]: Hello out Active pri 150 ip 10.208.204.1

2013 Apr 25 21:14:17.812708 hsrp: Vlan1712[111/V4]: hel 3 hol 10 auth test

2013 Apr 25 21:14:20.812683 hsrp: Vlan1712[111/V4]: Hello out Active pri 150 ip 10.208.204.1

2013 Apr 25 21:14:20.812705 hsrp: Vlan1712[111/V4]: hel 3 hol 10 auth test

Run in 3750 connevted via trunk to N5K

interface Vlan1712

ip address 10.208.204.10 255.255.255.0

standby 111 ip 10.208.204.1

standby 111 priority 190

standby 111 preempt

standby 111 authentication test

end

Debug

SW2_3750_LAB#

Apr 25 18:14:20: HSRP: Vl1712 Grp 111 Hello  out 10.208.204.10 Active  pri 190 vIP 10.208.204.1

Apr 25 18:14:20: HSRP: Vl1712 Grp 111 Hello  in  10.208.204.2 Active  pri 150 vIP 10.208.204.1

Apr 25 18:14:20: HSRP: Vl1712 Grp 111 Hello  out 10.208.204.10 Active  pri 190 vIP 10.208.204.1

SW2_3750_LAB#

It seem to be working OK in 3750 but N5K thinks he is the only one int the LAN and assumes itself as Active

NX-OS is

n5000-uk9.5.1.3.N2.1.bin

Hope you can help

Best Regards

Gonzalo Díaz

[thath02]

hi

Hope you can assist on nexus 5020.

we had a faulty psu from nexus 2232 Fex. A replacement was done. But fex did not restart after replacement. Had to reseat the psu and then fex restarted. Is this a default behaviour. Thank you.

Cisco Nexus Operating System (NX-OS) Software TAC support: http://www.cisco.com/tac

Documents: http://www.cisco.com/en/US/products/ps9372/tsd_products_support_series_home.html

Copyright (c) 2002-2012, Cisco Systems, Inc. All rights reserved.

The copyrights to certain works contained herein are owned by other third parties and are used and distributed under license.

Some parts of this software are covered under the GNU Public License. A copy of the license is available at http://www.gnu.org/licenses/gpl.html.

Software

BIOS: version 1.5.0

loader: version N/A

kickstart: version 5.1(3)N1(1a)

system: version 5.1(3)N1(1a)

power-seq: Module 1: version v1.2

BIOS compile time: 11/30/10

kickstart image file is: bootflash:///n5000-uk9-kickstart.5.1.3.N1.1a.bin

kickstart compile time: 2/7/2012 23:00:00 [02/08/2012 18:49:30]

system image file is: bootflash:///n5000-uk9.5.1.3.N1.1a.bin

system compile time: 2/7/2012 23:00:00 [02/08/2012 23:44:33]

PID: N2200-PAC-400W

[steffenwebb]

Hi,

I'm using the B22 FEX module in our HP C7000 chassis. Somehow, i'm recieving alot of messages in my log saying : Interface Ethernet xx/1/xx is down (Error disabled. Reason:ekeying triggered). My Fex is connected to a Nexus5596 : 5.2(1)N1(4). I did not see that kind of messages on my old 5010 switches.

What is the reason (all though i suspect servers booting) and can one disable the messages?

Regard Steffen Webb

[gnijs]

Same here. any way of disabling these messages ? even shutdown of interface won't help