Centralized Routing on Single Rack Small Data
Center Leaf Pair (not Border Leaf Pair)
The following items are required before you configure centralized routing on Single Rack
Small Data Center Leaf Pair.
- The device-role (leaf or border-leaf) are specified during the addition of the
devices to the fabric, prior to the “fabric configure”.
- Border-Leaf pair can exist in a CLOS or Small data center fabric irrespective of the
VRFs instantiated in the fabric are distributed or centralized.
- Device role border-leaf implies the leaf pair used at the edge (border) of the
fabric, and not restricted to the centralized routing.
- Tenant (PO, VRF, EPG, or BGP)
provisioning happens on a configured fabric.
- Only the Border-Leaf devices can act as Centralized Routers.
- Default routing-type for a VRF is “distributed” and you need to explicitly provide
the value “centralized” if needed.
- During the creation of the VRF as a CR (Centralized Router), EFA needs to
instantiate the VRF on a pair of Border-Leaf devices.
- If the fabric (CLOS or Small Data Center) has only one pair of Border-Leaf devices
then the same pair is chosen as the designated CRs (Centralized Routers) for the
VRF. Else, need to explicitly provide the Border-Leaf devices as the designated CRs
(Centralized Routers) during the creation of the VRF.
- EFA is designed to expand or compress with the addition or deletion of racks (rack =
MCT-pair) as per your rquirement.
- EFA cannot determine “a given fabric is a single rack small data center fabric and
can never be expanded beyond that”. Hence there is no specific automation for a
single-rack use case.
- For CR on a single rack small data center fabric, EFA recommends that you configure
the fabric with the device-role = border-leaf for both the MCT nodes.
- If you want to use Day 1 Centralized Routing
provisioning on a “Day 0 Configured Single Rack Leaf Small Data Center
Fabric”, then the same results in failure because CR can be instantiated
only on the border-leaf pair of the small data center fabric.
- You cannot recreate the fabric with device-role = border-leaf.
Fabric Setting for a single-rack-deployment
- A new fabric setting “single-rack-deployment” is introduced as
follows:
efa fabric setting update --name <non-clos-fabric-name> --single-rack-deployment <Yes|No>
- The fabric setting is applicable only for the Small Data Center fabric.
- Default value of single-rack-delployment = No.
- After upgrade from EFA 2.4.x to EFA 2.5.0, all the EFA 2.4.x small data center
fabrics have single-rack-deployment =No.
- Single Rack Deployment
- When the “single-rack-deployment = Yes” and the fabric is configured,
- You are not allowed to modify the single-rack-deployment from
Yes to No.
- The state is used
as an indicator to EFA that “a given fabric is a single rack non
clos fabric and will never be expanded beyond that”, so that EFA
can have specific automation for the specific scenario of
allowing the non-border-leaf rack act as CR (Centralized Router)
for single rack small data center leaf pair deployments.
- You cannot expand such a fabric. If you intend to expand such a
fabric, then you must delete the fabric and recreate the same
with “single-rack-deployment = No”.
- When the “single-rack-deployment = Yes” and the fabric is not
configured,
- You can modify the single-rack-deployment value from Yes to
No.
- Multi Rack Deployment
- When the “single-rack-deployment = No” and fabric is configured or
not-configured,
- You can modify the value of single-rack-deployment from No to
Yes, provided the existing number of racks in the fabric is
1.
- Fabric Device Add
- Validations are done to ensure the number of racks in the given fabric
adhere to the fabric settings.