Nexus 5548 and vfc Interfaces - WHY?

[lamav]

What is a vfc and why do we need to configure it? I find this extremely tedious.

I  have a Dell blade CNA connected to a Dell M8024-k FCoE transit module,  which is then connected to a Cisco Nexus 5K. The Cisco 5K's FC port is  in NPIV mode and is connected to a Brocade 300 switch. An FC target is  connected to the B300.

So, in configuring this set up, I see that, in the Cisco 5K, one has to map the CNA's Ethernet MAC-address to a vfc!

Why  do I have to do this mapping? You dont have to do this with Brocade.  For example, in another lab setup, I have a Dell M8428-k FCF (FCoE)  switch, which is a Brocade ODM, and there is no such mapping necessary.  You bring up a CNA at will, the CNA executees a FIP FLOGI, gets an FPMA  from the FC fabric switch, and a construct is seamlessly built  between that CNA (or perhaps more correctly stated, the N-Port component  of that CNA) and a LUN. NO MANUAL MAPPING is necessary.

Can  someone explain this Cisco vfc construct and why one has to engage in  this laborious task of mapping every CNA to a vfc? Just trying to  understand....perhaps I am missing something.

Thank you

[padramas]

Hello,

Virtual Fiber Channel ( vfc ) interfaces are used to apply FC features in FCoE link.

Check out the section " Cisco Nexus 5000 Series Virtual Fibre Channel Interfaces " in following link

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/white_paper_c11-560403.html

Additional guidelines on vfc configuration are  documented here

http://www.cisco.com/en/US/partner/docs/switches/datacenter/nexus5000/sw/fcoe/513_n1_1/b_Cisco_n5k_fcoe_config_gd_re_513_n1_1_chapter_0100.html#con_1288652

Padma

[lamav]

Thank you, Padramas....I dont understand why Cisco uses such a primitive way of accomplishing a link between the FCoE comnstruct and its associated FC element. Mapping each new server manually??? no way!

[padramas · Accepted solution]

Hello,

I am not FCoE expert but based on the above the mapping with MAC address is required only for hosts behind FCF.

This is inline with FCoE standards and following would be good read.

http://fcoe.com/09-056v5.pdf

FC-BB_E Structure and Concepts

Hopefully some one with more knowledge on this topic would be able to quickly provide relevant explanation for this feature and any alternate configuration options.

Padma