SD-Access VXLAN
MAC-in-UDP Encapsulation.
Extends vlans to support 16 million network segments in the same administrative domain.
Image courtesy of Lost In Transit
VXLAN is VTEP to VTEP.
- Outer-IP-SRC, VTEP that originated the packet
- Outer-IP-DST IP, VTEP that needs the packet.
- Outer-MAC-SRC, VTEP that created the packet.
- Outer-MAC-DST, the device to reach the VTEP, the gateway.
Multi-destination Support is provided by multicast.
VNI
- Virtual Network Identifier.
- 24 bits, 16 million segments.
- Get mapped to multicast groups.
- Used for macrosegmentation.
VTEP
- Virtual Tunnel End point.
- Originates and Terminates tunnels.
- push and pop VXLAN headers.
- Somitems a hypervisor (for app hosting)
VXLAN Segment
- Only devices with the same VNI can communicate.
- AKA Overlay Network
Layer 2 Overlay
The VNI is matched to a VLAN.
Layer 3 Overlay
The VNI is matched to a VRF.