Configure Fabric Extend
Use the following procedure to configure Fabric Extend (FE). A typical Fabric Extend deployment would be between a Main office and a Branch office.
To complete the Fabric Extend tunnel, you must configure Fabric Extend at both ends of the tunnel.
Optionally, you can configure a parallel tunnel between the same two nodes to create a backup Fabric Extend adjacency.
Before you begin
If using the tunnel originating address on a VRF, configure a CLIP and tunnel source IP address on the VRF.
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The tunnel source IP address must be on the GRT, not on a VRF.
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.
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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.
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
VRF is an optional parameter. If you do not configure a VRF, then FE uses the GRT.
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:
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Layer 2 — Fabric Extend VID (FE-VID)
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Layer 3 — Fabric Extend IP (FE-IP)
Procedure
What to do next
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.
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]][,...][slot/all][all]} |
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. |
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. |
src-ip <A.B.C.D> [vrf WORD<1-16>] |
Configures an additional source address and optional VRF to use as the parallel tunnel to create a backup adjacency. The VRF is the next-hop VRF to reach the logical tunnel destination IP associated with the parallel tunnel. To use an IPsec-encrypted tunnel as the parallel tunnel, ensure that you configure the same source IP address on the logical IS-IS interface and in the Fabric IPsec Gateway virtual machine. |
The following table defines parameters for the isis mtu command.
Variable |
Definition |
---|---|
<750-1600> |
Specifies the Maximum Transmission Unit (MTU) size in bytes for each IS-IS packet that uses this logical interface. The default is 1600. This command is available for Layer 3 core (FE-IP) interfaces only. |