Nexus 5K Port tracking feature on the FCOE ports

[andtran]

The IBM P7 blade server is connected to the Nexus 5K via FCOE port-channel (2x10G CNA), then the NX 5K uplink to the 6509 via ethernet port-channel (4x10G). Per 5.02 NXOS configuration guide, only physical FC ports can be linked ports. Please advise of how the FCOE can track (monitor) the uplink port?. What is the alternative method for FCOE port tracking ?

[Vincent La Bua]

link tracking is used to detect and minimize topology changes when an fc port goes down.

I imagine that vfc/fcoe configurations do not support multihop, unless using the N4k, this feature may not be necessary at this time for these port types.

Virtual Fibre Channel Interfaces
Fibre Channel over Ethernet (FCoE) encapsulation allows a physical Ethernet cable to simultaneously
carry Fibre Channel and Ethernet traffic. In Cisco Nexus 5000 Series switches, an FCoE-capable
physical Ethernet interface can carry traffic for one virtual Fibre Channel interface.

Native Fibre Channel and virtual Fibre Channel interfaces are configured using the same CLI commands.
Virtual Fibre Channel interfaces support only F mode, and offer a subset of the features that are
supported on native Fibre Channel interfaces.

The following capabilities are not supported for virtual Fibre Channel interfaces:
• SAN port channels.
• VSAN trunking. The virtual Fibre Channel is associated with one VSAN.
• The SPAN destination cannot be a virtual Fibre Channel interface.
• Buffer-to-buffer credits.
• Exchange link parameters (ELP), or Fabric Shortest Path First (FSPF) protocol.
• Configuration of physical attributes (speed, rate, mode, transmitter information, MTU size).
• Port tracking.

Also,

• Port tracking is not supported in NPV mode.

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/configuration/guide/cli/Nexus5000-NX-OS-ConfigurationGuide.pdf

Why exactly do you need this feature?

[andtran]

Hello Vincent,

We need the port tracking feature, cause there is only one ethernet port-channel uplink to the 6509 via SPT Layer-2. The FCOE is still up when the uplink goes down (6509 failed), then the P7 will continue to send traffic without faill-over.

I have two concerns in the 5K configuration guide. First, the virtual Fibre Channel interfaces do not support the SAN port channels. Second, each virtual Fibre Channel interface must be bound to an FCoE-enabled Ethernet interface. So can I map the san port-channel and multiple vfc to the same vsan ?. I configured it in the lab and it seems to be supported. Please verify the config below.

Thanks !!

Andy

interface san-port-channel 30
  channel mode active
  switchport mode E
  switchport trunk allowed vsan 111
  switchport trunk mode auto

interface vfc10
  bind interface port-channel10
  no shutdown

interface vfc11
  bind interface port-channel11
  no shutdown

vsan database
  vsan 111

vsan database
  vsan 111 interface vfc10
  vsan 111 interface vfc11
  vsan 111 interface san-port-channel 30

interface port-channel10
  description FCOE Port-chann to ESX server
  switchport mode trunk
  switchport trunk allowed vlan 100,200,1101
  spanning-tree port type edge trunk
  speed 10000

interface port-channel11
  description Port Channel to ESX #2
  switchport mode trunk
  switchport trunk allowed vlan 100,200,1101
  spanning-tree port type edge trunk
  speed 10000

Vlan 1101
   name FC_traffic
   fcoe vsan 111

[vdsudame]

The below config looks good. As n5k is not capable of doing IVR (inter vsan routing), vfc and san port channel have to be in the same vsan otherwise fcoe initiators will have problems communicating with FC storage across SAN switch connected to the n5k. Also we support bundling port channel interfaces in vfc to have the ability to do virtual port channels across the two n5ks. So once you bundle the port channel into vfc, you can then configure the same port channel in vpc. So as far as SAN is concerned, you will keep different fabrics but as far as Ethernet is concerned, it will be the same L2 domain.

hope this clarifies - V.

[andtran]

Thanks for your reply !

I have one last question in regard to vsan trunking via TE san port-channel. Can one san port channel (vsan trunking) carries multiple vsans for multiple vfc? See config below for clarification.

vsan database
  vsan 111 interface vfc10
  vsan 111 interface vfc11
vsan 111 interface san-port-channel 30
  vsan 222 interface vfc20
  vsan 222 interface vfc21
  vsan 222 interface san-port-channel 30

Thanks !!

Andy

[vdsudame]

Trunking port channel has the ability to carry multiple vsan traffic provided those vsans are existent on both sides of the port channel. The config you have put below, you need not assign two vsans to the same port channel, in fact it wont let you. When you try configuring for 'vsan 222 interface san-port-channel 30' it is going to reassign that same port channel to vsan 222 from 111. So at one time the port channel can be assigned to only one vsan but it can carry multiple vsan traffic. So even if you assign the san port channel to either vsan 111 or vsan 222 but if you get the port channel up and if you do a 'show interface san-port-channel 30' you should see it passing both vsan 222 and 111 and any other vsan existent on the switch provided you have it on the other side.

Hope this clarifies, thanks, Vinayak

[vdsudame]

currently we dont have the ability to port track FCoE ports. Right now we support error disable detect and recovery on thernet interfaces

Configuring Ethernet Interfaces

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/layer2/421_n1_1/Cisco_n5k_layer2_config_gd_rel_421_n1_1_chapter3.pdf

look at  page 5,10,11.