Home / Datacenter / Dynamic Fibre-Channel over Ethernet- FCOE

Dynamic Fibre-Channel over Ethernet- FCOE


Today I am going to talk about the Dynamic FCOE ( Fiber Channel over Ethernet ). Fibre-Channel over Ethernet (FCoE) allows the benefits of Fabricpath, including Equal Cost Multi-pathing (ECMP), to be leveraged by Storage Area Networks [SAN] deployments while keeping SAN A - B isolation. The SAN A - B isolation is maintained physically at the 'Leaf Layer' while logically isolated through the FabricPath domain.
Dynamic FCoE automatically instantiates VE ports over the FabricPath domain and provides the following benefits:
  • Create a logical, rather than physical, SAN A/B seperation.
  • Efficiently load balance multiprotocol traffic within the data center.
  • Dynamically establish relationships between switches, reducing the possibility for human error during configurations.
  • Improved high availability percentages as the scale increases.

Fig 1.1- Dynamic FCOE



Dynamic VFC Installation
  • Every FCF leaf is uniquely identified by a global FCF-MAC address.
  • Every FCF leaf floods an FIP unsolicited multicast discovery advertisement to ALL-FCF MAC addresses and source MAC addresses that are set to its global FCF-MAC address on the FabricPath-enabled FCoE VLANs. This is triggered by two factors: Feature FCoE enabled on the leaf and Fabricpath enabled on the FCoE vlans.
  • All FCF leafs on this FabricPath cloud should receive this multicast advertisement on the corresponding FCoE-enabled FP VLAN. Upon receiving this FIP multicast frame, a dynamic VFC in VE mode is created between the two FCF leaf nodes.
  • Only one dynamic VFC in TE mode is between any two FCF leafs.
  • The dynamic VFCs can be differentiated based on their VFC ID range. All dynamic VFCs obtain an ID that is greater than 32000.
  • The VFC might have multiple FabricPath FCoE VLANs up. The VLANs might or might not be in the same topology.
  • Every FCF leaf is one hop away. For all VE paths that use FabricPath, a default fixed FSPF cost value is used.

The below configuration assumes FabricPath is already up and adjacencies are formed and will focus on the FCoE aspects of the configuration

1. Enable FCoE on the leaf switches.
feature fcoe

2. Enable FabricPath and FCoE on your vlan and create the VSAN.
!
vlan 100
  fcoe vsan 100
  mode fabricpath
!
vsan database 
  vsan 100
!

3. Enable FCoE QoS on all switches in the FabricPath domain.
system qos
  service-policy type qos input fcoe-default-in-policy
  service-policy type queuing input fcoe-default-in-policy
  service-policy type queuing output fcoe-default-out-policy
  service-policy type network-qos fcoe-default-nq-policy

4. Change FKA advertisment period to 20 seconds as best practice
fcoe fka-adv-period 20

5. You must assign the highest FabricPath cost to the MCT if there is a vPC+ MCT on the FCF leafs.
Note: Maximizing the ISIS metric prevents the vPC+ FCF leafs from using the peer-link as a forwarding path

fabricpath isis metric 16777210