7
•
VLAN access mode
—Ethernet frames received from or sent to the local site must contain
802.1Q VLAN tags.
{
For an Ethernet frame received from the local site, the VTEP removes all its 802.1Q VLAN
tags before forwarding the frame.
{
For an Ethernet frame destined for the local site, the VTEP adds 802.1Q VLAN tags to the
frame before forwarding the frame.
In VLAN access mode, VXLAN packets sent between sites do not contain 802.1Q VLAN tags.
You can use different 802.1Q VLANs to provide the same service in different sites.
•
Ethernet access mode
—The VTEP does not process the 802.1Q VLAN tags of Ethernet
frames received from or sent to the local site.
{
For an Ethernet frame received from the local site, the VTEP forwards the frame with the
802.1Q VLAN tags intact.
{
For an Ethernet frame destined for the local site, the VTEP forwards the frame without
adding 802.1Q VLAN tags.
In Ethernet access mode, VXLAN packets sent between VXLAN sites contain 802.1Q VLAN
tags. You must use the same VLAN to provide the same service between sites.
ARP flood suppression
ARP flood suppression reduces ARP request broadcasts by enabling the VTEP to reply to ARP
requests on behalf of VMs.
As shown in
, this feature snoops ARP packets to populate the ARP flood suppression table
with local and remote MAC addresses. If an ARP request has a matching entry, the VTEP replies to
the request on behalf of the VM. If no match is found, the VTEP floods the request to both local and
remote sites.
Figure 7 ARP flood suppression
ARP flood suppression uses the following workflow:
1.
VM 1 sends an ARP request to obtain the MAC address of VM 7.
2.
VTEP 1 creates a suppression entry for VM 1, and floods the ARP request in the VXLAN.
