H3C S7500E-XS Series, Configuration Manual

Page: 11 / 39

4
A VSI's MAC address table includes the following types of MAC address entries:
•
Local MAC —Dynamic MAC entries learned from the local site. The outgoing interfaces are
site-facing interfaces on which the MAC addresses are learned. VXLAN does not support
manual local-MAC entries.
•
Remote MAC —MAC entries learned from a remote site, including static, dynamic, and
OpenFlow MAC entries. The outgoing interfaces for the MAC addresses are VXLAN tunnel
interfaces.
{
Static —Manually added MAC entries.
{
Dynamic —MAC entries learned in the data plane from incoming traffic on VXLAN tunnels.
The learned MAC addresses are contained in the inner Ethernet header.
{
OpenFlow —MAC entries issued by a remote controller through OpenFlow.
For a remote address, the manual static entry has higher priority than the dynamic entry.
Traffic forwarding
The VTEP uses the following processes to forward traffic:
•
Unicast process —Applies to destination-known unicast traffic.
•
Flood process —Applies to multicast, broadcast, and unknown unicast traffic.
When the VTEP forwards VXLAN traffic, it processes the 802.1Q tag in the inner Ethernet header
depending on the VSI access mode (VLAN or Ethernet mode). In VLAN access mode, sites can use
different VLANs to provide the same service. For more information, see "
Access modes of VSIs ."
Unicast
The following process (see Figure 4 ) applies to a known unicast frame between sites:
1. The source VTEP encapsulates the Ethernet frame in the VXLAN/UDP/IP header.
In the outer IP header, the source IP address is the source VTEP's VXLAN tunnel source IP
address. The destination IP address is the VXLAN tunnel destination IP address.
2. The source VTEP forwards the encapsulated packet out of the outgoing VXLAN tunnel
interface found in the VSI's MAC address table.
3. The intermediate transport devices (P devices) forward the frame to the destination VTEP by
using the outer IP header.
4. The destination VTEP removes the headers on top of the inner Ethernet frame. It then performs
MAC address table lookup in the VXLAN's VSI to forward the frame out of the matching
outgoing interface.