Configure Fabric Extend

Use the following procedure to configure Fabric Extend (FE) between a Main office and a Branch office, which is a typical deployment.

You must configure the tunnel source address and logical interface on both ends of the tunnel to complete this procedure.

Before you begin

  • If using the tunnel originating address, the logical interface 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

      To configure Fabric Extend using a tunnel source IP address on the GRT, use separate IP addresses for the SPBM IP Shortcuts (ip source-address) and the Fabric Extend ip-tunnel-source address. Exclude the ip-source-address address with an IS-IS accept policy if you want these IP addresses to be the same. You cannot use the redistribute command with a route-map exclusion.

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

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

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

About this task

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.

Note

Note

VRF is an optional parameter. If you do not configure a VRF, then FE uses the GRT.

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.

For a logical IS-IS interface, Layer 2 and Layer 3 refer to the following use cases:

  • Layer 2 — Fabric Extend VID (FE-VID)

  • Layer 3 — Fabric Extend IP (FE-IP)

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 {vlan-id[-vlan-id][,...]} primary-vid <2–4059> port <slot/port> mlt PT_MLT<1-512> [name WORD<1–64>]

      Note

      Note

      The primary VLAN ID (primary-vid must be one of the VIDs in the vid {vlan-id[-vlan-id][,...]}.

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 (FE-VID)

Variable

Value

<1–255>

Specifies the index number that uniquely identifies this logical interface.

mlt PT_MLT<1-512>

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.

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.

primary-vid <2–4059>

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

vid {vlan-id[-vlan-id][,...]}

Specifies the list of VLANs that are associated with this logical interface.
Table 2. Layer 3 core (FE-IP)

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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