Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 

Configuring VLANs for FCoE Traffic on an FCoE Transit Switch

 

When you configure a switch as a Fibre Channel over Ethernet (FCoE) transit switch, you must configure a VLAN that transports only FCoE traffic. FCoE traffic requires a dedicated VLAN and cannot share a VLAN with any other type of traffic. Because FCoE traffic is tagged traffic, the port (or interface) mode cannot be access mode, it must be either tagged-access port-mode (for switches that run the original CLI) or trunk interface-mode (for switches that run the Enhanced Layer 2 Software (ELS) CLI).

However, each interface that belongs to an FCoE VLAN must not only transport the tagged FCoE traffic, it must also transport the untagged FCoE Initialization Protocol (FIP) traffic. FIP communicates with the storage area network (SAN) Fibre Channel (FC) switch to set up the FCoE session for the FCoE client.

To transport untagged traffic on a tagged-access or trunk mode interface, the interface must have a native VLAN configured on it. Therefore, each interface that belongs to an FCoE VLAN must also have a native VLAN on it.

There are slight differences in the way you configure a native VLAN on an interface, depending on whether the switch uses the ELS CLI or the original CLI. This topic describes both methods.

Note

FCoE VLANs (any VLAN that carries FCoE traffic) support only Spanning Tree Protocol (STP) and link aggregation group (LAG) Layer 2 features.

FCoE traffic cannot use a standard LAG because traffic might be hashed to different physical LAG links on different transmissions. This breaks the (virtual) point-to-point link that Fibre Channel traffic requires. If you configure a standard LAG interface for FCoE traffic, FCoE traffic might be rejected by the FC SAN.

QFabric systems support a special LAG called an FCoE LAG, which enables you to transport FCoE traffic and regular Ethernet traffic (traffic that is not FCoE traffic) across the same link aggregation bundle. Standard LAGs use a hashing algorithm to determine which physical link in the LAG is used for a transmission, so communication between two devices might use different physical links in the LAG for different transmissions. An FCoE LAG ensures that FCoE traffic uses the same physical link in the LAG for requests and replies in order to preserve the virtual point-to-point link between the FCoE device converged network adapter (CNA) and the FC SAN switch across the QFabric system Node device. An FCoE LAG does not provide load balancing or link redundancy for FCoE traffic. However, regular Ethernet traffic uses the standard hashing algorithm and receives the usual LAG benefits of load balancing and link redundancy in an FCoE LAG.

Note

To configure an FCoE VLAN on a QFX3500 switch that you are using as an FCoE-FC gateway, you must also configure an FCoE VLAN interface as described in Configuring an FCoE VLAN Interface on an FCoE-FC Gateway. (Only the QFX3500 switch supports FCoE-FC gateway configuration.)

FCoE VLAN configuration includes:

  • Configuring a VLAN to use as a dedicated FCoE VLAN

  • Configuring the interface members of the FCoE VLAN.

  • Configuring a native VLAN for FIP traffic.

This topic includes two configuration procedures, one for switches that run the original CLI, and one for switches that run the ELS CLI.

Original CLI Configuration

To configure an FCoE VLAN on a non-ELS switch:

  1. Configure a dedicated FCoE VLAN:
    [edit vlans]

    user@switch# set vlan-name vlan-id vlan-id



    For example, to configure a VLAN named fcoe_vlan with a VLAN ID of 100 as the FCoE VLAN:

    [edit vlans]

    user@switch# set fcoe_vlan vlan-id 100



  2. Configure the FCoE VLAN on the interface (use ethernet-switching as the family and tagged-access as the port mode):
    [edit interfaces]

    user@switch# set interface-name unit unit family family port-mode mode vlan members vlan-name



    For example, to configure the interface xe-0/0/10 as a member of the FCoE VLAN fcoe_vlan:

    [edit interfaces]

    user@switch# set xe-0/0/10 unit 0 family ethernet-switching port-mode tagged-access vlan members fcoe_vlan



  3. Configure the Ethernet interface membership in the FCoE VLAN:
    [edit vlans]

    user@switch# set vlan-name interface interface-name



    For example, to assign the interface xe-0/0/10.0 to the FCoE VLAN named fcoe_vlan:

    [edit vlans]

    user@switch# set fcoe_vlan interface xe-0/0/10.0



  4. Configure a native VLAN for the untagged FIP traffic:
    [edit vlans]

    user@switch# set native vlan-id vlan-id



    For example, to configure the native VLAN with a VLAN ID of 1:

    [edit vlans]

    user@switch# set native vlan-id 1



  5. Assign member interfaces to the native VLAN:
    [edit interfaces]

    user@switch# set interface-name unit unit family family native-vlan-id vlan-id



    For example, to configure the interface xe-0/0/10 as a member of the native VLAN with the native VLAN ID 1:

    [edit interfaces]

    user@switch# set xe-0/0/10 unit 0 family ethernet-switching native-vlan-id 1



ELS CLI Configuration

To configure an FCoE VLAN on a switch running ELS:

  1. Configure a dedicated FCoE VLAN:
    [edit vlans]

    user@switch# set vlan-name vlan-id vlan-id



    For example, to configure a VLAN named fcoe_vlan with a VLAN ID of 100 as the FCoE VLAN:

    [edit vlans]

    user@switch# set fcoe_vlan vlan-id 100



  2. Configure the FCoE VLAN on the interface (use ethernet-switching as the family and trunk as the interface mode):
    [edit interfaces]

    user@switch# set interface-name unit unit family family interface-mode mode vlan members vlan-name



    For example, to configure the interface xe-0/0/10 as a member of the FCoE VLAN fcoe_vlan:

    [edit interfaces]

    user@switch# set xe-0/0/10 unit 0 family ethernet-switching interface-mode trunk vlan members fcoe_vlan



  3. Configure the Ethernet interface membership in the FCoE VLAN:
    [edit vlans]

    user@switch# set vlan-name interface interface-name



    For example, to assign the interface xe-0/0/10.0 to the FCoE VLAN named fcoe_vlan:

    [edit vlans]

    user@switch# set fcoe_vlan interface xe-0/0/10.0



  4. Configure a native VLAN on the physical Ethernet interface for the untagged FIP traffic:
    [edit interfaces]

    user@switch# set interface-name native-vlan-id vlan-id



    For example, to configure the native VLAN on interface xe-0/0/10 with a VLAN ID of 1:

    [edit interfaces]

    user@switch# set xe-0/0/10 native-vlan-id 1



  5. Configure the Ethernet interface as a member of the native VLAN:
    [edit interfaces]

    user@switch# set interface-name unit unit family family vlan members native-vlan-id
    Note

    The native-vlan-id number must be the same as the native VLAN ID number that you configured on the physical Ethernet interface (see step 4).



    For example, to configure the interface xe-0/0/10 as a member of the native VLAN with the native VLAN ID 1:

    [edit interfaces]

    user@switch# set xe-0/0/10 unit 0 family ethernet-switching vlan members 1