Configure Fabric Extend

Before you begin

The tunnel source IP address can be a brouter port IP, a CLIP IP, or a VLAN IP.

For information about product support, see Fabric Extend Considerations.

Important

Important

Switches that support a single active VRF have feature interactions with Fabric Extend. For more information, see VRF Lite Configuration Rules. To assist with the single-active VRF restrictions, an overlay parameter exists for the ip-tunnel-source-address command.

If using the tunnel originating address on the GRT, Fabric Extend has the following requirements:

  • The tunnel source IP address must be on the GRT, not on a VRF.

    Note

    Note

    A best practice is to use separate IP addresses for the SPBM IP Shortcuts ip-source-address command and the Fabric Extend ip-tunnel-source-address command. However, if you want these IP addresses to be the same, you MUST exclude the ip-source-address address with an IS-IS accept policy. You cannot use the redistribute command with a route map exclusion.

    Specify a CLIP interface to use as the source address for SPBM IP shortcuts.

  • If IP Shortcuts is enabled, you must configure an IS-IS accept policy or exclude route-map to ensure that tunnel destination IP addresses are not learned through IS-IS.

If you are using the tunnel originating address on a VRF, configure a CLIP and tunnel source IP address on the VRF.

About this task

Configuring Fabric Extend consists of two primary tasks: configuring the tunnel source address and configuring the logical interface. These tasks must be completed on both ends of the tunnel.

Note

Note

VRF is an optional parameter. If a VRF is not configured, then FE uses the GRT.

Procedure

  1. Enter IS-IS Router Configuration mode:

    enable

    configure terminal

    router isis

  2. Configure the IP tunnel source address:

    ip-tunnel-source-address <A.B.C.D> [vrf WORD<1–16>] [overlay]

  3. Enter Global Configuration mode:

    exit

  4. Use one of the following commands to create a logical IS-IS interface:

    • In a network with a Layer 3 Core, enter logical-intf isis <1–255> dest-ip <A.B.C.D> [name WORD<1–64>]

    • In a network with a Layer 2 Core, enter logical-intf isis <1–255> vid <list of vids> primary-vid <2–4059> port <slot/port> mlt <mltId> [name WORD<1–64>]

      Note

      Note

      The primary VLAN ID (primary-vid must be one of the VIDs in the vid <list of vids>.

Variable Definitions

The following table defines parameters for the ip-tunnel-source-address command.

Variable

Value

<A.B.C.D>

Specifies the IS-IS IPv4 tunnel source address, which can be a brouter interface IP, a CLIP IP, or a VLAN IP.

overlay

Permits the configuration of the tunnel source address even though it belongs to a VRF with an attached I-SID.

vrf WORD<1–16>

Specifies the VRF name associated with the IP tunnel.

The following tables define parameters for the logical-intf isis command, depending on whether you have a Layer 2 or Layer 3 core.

Table 1. Layer 2 core

Variable

Value

<1–255>

Specifies the index number that uniquely identifies this logical interface.

port {slot/port[/sub-port] [-slot/port[/sub-port]] [,...]}

Specifies the physical port that the logical interface is connected to in a Layer 2 network.

vid <list of vids>

Specifies the list of VLANs that are associated with this logical interface.

primary-vid <2–4059>

Specifies the primary tunnel VLAN ID associated with this Layer 2 IS-IS logical interface.

mlt <mltId>

Specifies the MLT ID that the logical interface is connected to in a Layer 2 network.

name WORD<1–64>

Specifies the administratively-assigned name of this logical interface, which can be up to 64 characters.
Table 2. Layer 3 core

Variable

Value

<1–255>

Specifies the index number that uniquely identifies this logical interface.

dest-ip <A.B.C.D>

Specifies the tunnel destination IP address of the remote BEB.

name WORD<1–64>

Specifies the administratively-assigned name of this logical interface, which can be up to 64 characters.
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