FM/DCNM Slow Discovery

[david-davis]

For the past few months I have had an issue with slow discovery of my MDS9134's via Fabric Manager (SA).  We have a pair of 9124's at another site that discover and open instantly, however the pair of 9134's, which are local, take about 5-10 minutes each.

I have recently upgraded the switches and FM to 5.0.7.....but this did not help the issue.  I also tried installing and using DCNM 5.2.2a but it has the same problem.

I have tried uninstalling FM/DCNM completely and reinstalling.....and when I try do to my initial discovery, I get this messsage:  "Fabric is not discovered yet.  Keep waiting?"  If I select YES to continue waiting, I receive that message a couple more times and then the fabric is finally discovered and I can open it and everything seems to operate normally.  However, once I close FM and reopen it, I have the same delay just trying to open one of the already discovered 9134 fabrics and I receive this message:  "Fabric_xxxxxxx is in the process of being discovered.  Please wait before trying again."

Does anyone have an idea on where to start my troubleshooting for this issue?

****We recently connected our MDS9134's to our UCS 6248's via a FC Port Channel.....I wonder if this may be part of the issue??***

[Vu Phan]

Hello David,

The last note is important.  Since you have UCS 6248 connected to MDS9134 via FC port channel, so it is one fabric. The FMSA will try to discover UCS also and will timeout. That timeout make discovery longer.

You will need to do the following to get it working:

- all switches and UCS must have the same snmp username/password

- on UCS enable snmpv3 on UCS

- on UCS create a new snmp account fmadmin and assign a password

- on your MDS 9134, create snmp account with the same fcadmin user and password for all switches in this fabric

- on FMSA, remove fabric with MDS1934

- Rediscover fabric, use fmadmin/password created previously

You should see the discovery faster

Let me know if this help

[david-davis]

Vu,

Thank you for your response......after trying your instructions I am still unable to make this work.  From what I can tell......to enable snmpv3 on UCS you only need to set the Admin State radio button to ENABLED and then create a SNMP user under the SNMP USERS sections.  I created fmadmin with MD5 and assigned a password (no AES 128, no Privacy Password).  Do I need to set the Community/Username field to fmadmin as well and configure a Trap?

On the MDS9134 I issued this command to create the user:

snmp-server user fmadmin network-operator auth mypassword

Here are the two running config lines for the fmadmin acct on the MDS and UCS:

MDS:  snmp-server user fmadmin network-operator auth md5 removedencryptionstring localizedkey

UCS:  snmp-server user fmadmin network-operator auth md5 removedencryptionstring localizedkey

Is the localizedkey going to prevent this from working?  Do I have to have create a community name of fmadmin on the MDS as well?

Thank you again for your assistance.

[Vu Phan]

Hello David,

Please also create same community as the other switches

Make sure when discovery,use user fmadmin/password

thanks

vu

[david-davis]

Vu,

I understand all SNMP community strings need to be indentical.....however, it appears that in UCS they want you to enter the snmpv3 username in the community field (very confusing).  So in addition to our standard community strings on our MDS switches, do I need to add an additonal community labeled FMADMIN?

I am using the fmadmin/password for the discovery process......still slow and when I finally get in after 10 minutes or so it shows my UCS switch with a red line thru it.

I may just go ahead and open a case with TAC.  I do appreciate you trying to help.

Thanks,

David

[Kshitij Purwar]

Hi Jim,

I really need your help to figure out,can we add UCS 6140 FI to DCNM for configuration/TRAP alerts.

Thanks

kshitij

[jihicks]

Sure Kshitij,

Cisco UCS Manager GUI Configuration Guide, Release 2.2

Configure a trap destination of the IP address for DCNM.

Use version 2C, community public, udp-port 2162

Enable SNMP and save the config.

It will take a short while for DCNM to turn off the "no traps" warning.

Jim

[Kshitij Purwar]

Hi Jim,

appreciate your quick reply.

I have added Nexus 5020 with UCS FI 6140,my nexus are working fine,but i see timeout for 6140 on san-client as well on summary page.

PFA Screen shot.

[Kshitij Purwar]

Hi Jim,

Need your expert comments to come out from this issue.

Regards

kshitij

[jihicks]

Hi David,

There is also a new option in DCNM 5.2(2a) and above where you can turn off discovery of NPV switches, such as the UCS in this case.  Set this to "false" and restart DCNM Server. 

You can edit the "server.properties" file:

# Allow NPV discovery:

# (Default to true)

fabric.enableNpvDiscovery=true <<<

You can also change this option via the web client ( Web User Interface ), select the Admin Tab and  then "Server Properties". The option is at the bottom of the "GENERAL->DATA SOURCES FABRIC - POLLING" section.

Don't forget to restart DCNM Server after the change.

Best regards,

Jim

[david-davis]

Thanks Jim!.....that does indeed cure the speed issue!!  I would really like to figure out why I cannot configure it work with NPV discovery.  I was hoping to maybe have a single plane of mgmt between UCS and our MDS switches.  Not really sure what kind of insight DCNM gives you into UCS anyway.....

Regards,

David

[jihicks]

Hi David,

By default, FM/DCNM uses SNMPV3.  In the MDS, this can be seen as the "snmp-server user" ID and password.

By default, the UCS does not have SNMP enabled nor will it allow you to use "admin" as the SNMPV3 userid.

You can only have one userid and password on the  fabric  tab on the control panel for FM/DCNM, so the same one has to be  defined  and used for all switches ( including the fabric interconnect on  the  UCS ) in the fabric. 

It looks like you have  defined the  userid and passwords:

(1)However, these have role network-operator and you are gonna want this to be network-admin, so that you can do zoning ( if you are using the default role definitions ).

(2)Make sure this password is being used  on both  the fabric and open tabs on the Control Panel for FM/DCNM (  there are  two places ).

http://www.cisco.com/en/US/docs/unified_computing/ucs/sw/gui/config/guide/1.4/UCSM_GUI_Configuration_Guide_1_4_chapter6.html#task_49D35C84025E4495BBE50BE01CA7D0D0

Not sure what version of FM/DCNM or UCS Firmware you are using but check these bugs:

CSCtx45591    UCS discovery fails via DCNM

CSCtq73035    DM does not support UCS 6248 Fabric Interconnect starting from UCS 2.0  release.

Best regards,

Jim