Dell S3048-ON EMC Networking Virtualization Overlay with BGP EVPN - Page 11

BGP EVPN VXLAN operation, Integrated routing and bridging IRB, Anycast gateway, Indirect gateway

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3.2 3.3 3.4 3.5 BGP EVPN VXLAN operation EVPN uses BGP to exchange endpoint MAC and IP address information between VTEPs. When a host sends a packet to an endpoint, the switch looks up the routing table for a match. If it finds a match that exists behind another VTEP, the packet is encapsulated with VXLAN and UDP headers and encapsulated again with outer IP and Ethernet headers for transport over the leaf-spine network. When the packet arrives at the destination VTEP, the outer Ethernet, IP, UDP, and VXLAN headers are removed, and the switch sends the original packet to the endpoint. Integrated routing and bridging (IRB) With EVPN, overlay routing occurs on leaf switches. As of OS10EE version 10.4.3.1, Dell EMC PowerSwitches support asymmetric IRB. This means that overlay routing, also known as RIOT, occurs on ingress leaf switches. The packets travel over the leaf and spine network on the destination VNI. When the packets arrive at the destination VTEP, they are bridged to the endpoint. Anycast gateway Anycast gateways with the same IP address are deployed to each leaf pair connected to servers. The anycast gateway IP address is set as the default gateway for all VMs on that virtual network. VMs on VNIs with anycast gateways use the same gateway information while behind different leaf pairs. When those VMs communicate with different networks, their local leaf switches always do the routing. This replaces Virtual Router Redundancy Protocol (VRRP) and enables VMs to migrate from one leaf pair to another without the need to change the network configuration. Indirect gateway As shown in Figure 6, VNI C does not have an anycast gateway configured. It uses an indirect gateway attached to the border leafs instead. In this case, the indirect gateway is a physical switch acting as a firewall/gateway to the Internet. When a VM on VNI C sends a packet destined for another network, it is tunneled to the border leaf pair where it is forwarded to the indirect gateway which makes the proper forwarding decisions according to its routing table. In this deployment example, VNIs A and B also use the indirect gateway to access the Internet by configuring static routes. 11 Dell EMC Networking Virtualization Overlay with BGP EVPN

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Dell EMC Networking Virtualization Overlay with BGP EVPN
3.2
BGP EVPN VXLAN operation
EVPN uses BGP to exchange endpoint MAC and IP address information between VTEPs. When a host
sends a packet to an endpoint, the switch looks up the routing table for a match. If it finds a match that exists
behind another VTEP, the packet is encapsulated with VXLAN and UDP headers and encapsulated again
with outer IP and Ethernet headers for transport over the leaf-spine network. When the packet arrives at the
destination VTEP, the outer Ethernet, IP, UDP, and VXLAN headers are removed, and the switch sends the
original packet to the endpoint.
3.3
Integrated routing and bridging (IRB)
With EVPN, overlay routing occurs on leaf switches. As of OS10EE version 10.4.3.1, Dell EMC
PowerSwitches support asymmetric IRB. This means that overlay routing, also known as RIOT, occurs on
ingress leaf switches. The packets travel over the leaf and spine network on the destination VNI. When the
packets arrive at the destination VTEP, they are bridged to the endpoint.
3.4
Anycast gateway
Anycast gateways with the same IP address are deployed to each leaf pair connected to servers. The anycast
gateway IP address is set as the default gateway for all VMs on that virtual network. VMs on VNIs with
anycast gateways use the same gateway information while behind different leaf pairs. When those VMs
communicate with different networks, their local leaf switches always do the routing. This replaces Virtual
Router Redundancy Protocol (VRRP) and enables VMs to migrate from one leaf pair to another without the
need to change the network configuration.
3.5
Indirect gateway
As shown in Figure 6, VNI C does not have an anycast gateway configured. It uses an indirect gateway
attached to the border leafs instead. In this case, the indirect gateway is a physical switch acting as a
firewall/gateway to the Internet. When a VM on VNI C sends a packet destined for another network, it is
tunneled to the border leaf pair where it is forwarded to the indirect gateway which makes the proper
forwarding decisions according to its routing table.
In this deployment example, VNIs A and B also use the indirect gateway to access the Internet by configuring
static routes.