In an OSPF implementation for an IP fabric, the host-connected interfaces of the leaf node should be included as passive interfaces to prevent OSPF from sending or receiving OSPF packets on these interfaces while still allowing the network to be advertised. This reduces unnecessary OSPF traffic on interfaces that connect to end devices. The spine-connected interfaces of the leaf node should be included in the OSPF configuration to allow OSPF routing between leaf and spine nodes, which is essential for the underlay network to function.
Route targets permit granular control of per-VNI type-2 and EVPN type-3 routes across an entire overlay network. They define how routes are imported and exported between different virtual routing and forwarding instances (VRFs), thus effectively managing the distribution of routes within the overlay network.
To ensure that traffic can be forwarded at line rate in an IP fabric underlay network, the oversubscription model used should be 1:1. This means that the available bandwidth will match the required bandwidth, ensuring no congestion and optimal performance. This model ensures that there is no oversubscription, which aligns with the requirement to forward traffic at line rate.
In an EVPN-VXLAN fabric, DHCP relay allows the DHCP client and DHCP server to reside in different routing instances. This feature is essential for enabling DHCP relay functionality across routed infrastructures where clients and servers are not within the same VLAN or subnet. Additionally, both virtual gateway and anycast gateway addressing are supported in EVPN-VXLAN fabrics. These technologies enhance the fabric's scalability and redundancy by allowing multiple devices to share the same IP address for gateway functionalities.
VXLAN stitching is supported in both 3-stage and 5-stage fabrics, making it a versatile solution for different data center architectures. Additionally, VXLAN stitching is particularly beneficial and ideal for medium to large data center designs. It helps in managing scalability and maintaining efficient communication without the need for a full mesh of VXLAN tunnels, which can be complex and less efficient.