Basics about Cisco ACI GOLF L3Out

Cisco ACI GOLF L3Out

As part of the Cisco ACI infrastructure, we are going to introduce a concept called Cisco ACI GOLF. Cisco came up with an alternative L3Out solution via the Spine switches in the Spine-Leaf architecture via the GOLF routers that are used in the GOLF architecture which are called the L3Out devices in the GOLF architecture. GOLF is integrated into Cisco's ACI infrastructure.

With Cisco ACI GOLF, ACI fabric WAN connectivity is considerably more powerful and scalable. Routers connected to spine switches use the BGP EVPN protocol over OSPF.

Fig 1.1- GOLF in Cisco ACI

GOLF uses a single session to connect tenants to the WAN routers connecting spine switches. By reducing the number of tenants BGP session and the configuration effort required to configure them all, these tenants BGP sessions near the DCIG advance control plane scale.

Through Layer 3 sub interfaces on spine fabric ports, the network is stretched out. There is no support for transit routing using Golf.

GOLF physical connectivity to a spine switch is specified by an external outside Layer 3 network (L3extOut) under the infrastructure tenant

Points to be taken care 

  • For golf routers to accept traffic from Cisco ACI, they must advertise at least one route. Until Cisco ACI receives a route from the external routers, no tunnel is created between leaf switches and the external routers.
  • Golf is supported by all Cisco Nexus 9000 Series ACI-mode switches, Cisco Nexus 9500 platform ACI-mode switch line cards, and Cisco Nexus 9500 platform fabric modules.
  • When configuring GOLF on a spine switch, wait for the control plane to converge before configuring GOLF on another spine switch.
  • There can be multiple spine switches added to multiple GOLF outside networks (GOLF L3Outs), but the provider labels must be unique for each L3Out.This means that in this case each of the L3extOuts must have a different OSPF Area, along with different loopback addresses.
  • BGP EVPN advertises the tenant routes in this L3extOut towards the matching provider L3Out of the infra tenant. If necessary, increase this for ACI WAN Interconnect peers.
We will talk about the configurations on GOLF in our next GOLF ACI article.