Administrator Guide

Components of VXLAN Frame Format
Some of the important elds of the VXLAN frame format are described below:
Outer Ethernet
Header:
The Outer Ethernet Header consists of the following components:
• Destination Address: Generally, it is a rst hop router's MAC address when the VTEP is on a dierent address.
• Source Address : It is the source MAC address of the router that routes the packet.
• VLAN: It is optional in a VXLAN implementation and will be designated by an ethertype of 0×8100 and has an
associated VLAN ID tag.
• Ethertype: It is set to 0×0800 because the payload packet is an IPv4 packet. The initial VXLAN draft does not
include an IPv6 implementation, but it is planned for the next draft.
Outer IP Header: The Outer IP Header consists of the following components:
• Protocol: It is set to 0×11 to indicate that the frame contains a UDP packet .
• Source IP: It is the IP address of originating VTEP.
• Destination IP: : It is the IP address of target VTEP.
Outer UDP Header: The Outer UDP Header consists of the following components:
• Source Port: Entropy of the inner frame. The entropy could be based on the Inner L2 header or Inner L3
header.
• VXLAN Port : IANA-assigned VXLAN Port (4789).
• UDP Checksum: The UDP checksum eld is transmitted as zero. When a packet is received with a UDP
checksum of zero, it is accepted for decapsulation.
VXLAN Header :
• VXLAN Flags : Reserved bits set to zero except bit 3, the rst bit, which is set to 1 for a valid VNI
• VNI: The 24-bit eld that is the VXLAN Network Identier
• Reserved: A set of elds, 24 bits and 8 bits, that are reserved and set to zero .
Frame Check
Sequence (FCS):
Note that the original Ethernet frame's FCS is not included, but new FCS is generated on the outer Ethernet
frame.
Conguring and Controlling VXLAN from the NVP
Controller GUI
You can congure and control VXLAN from the NVP controller GUI, by adding a hardware device to NSX and authenticating the device.
1 Generate a certicate in your system and add it to the NSX before adding a hardware device for authentication.
To generate a certicate, use the following command:
• crypto cert generate self-signed cert-file flash://vtep-cert.pem key-file flash://vtep-
privkey.pem
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Virtual Extensible LAN (VXLAN)