Allied Telesis AT-WA7500 - Manual (Page 122)

5 - Configuring the Spanning Tree
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MAC frames that are forwarded outbound are encapsulated in the root
access point, forwarded through the network, unencapsulated by the
access point at the remote end of the IP tunnel, and forwarded to the
appropriate access point (if necessary) for delivery to the destination
end device.
Inbound Frames
Frames are forwarded inbound (to the primary LAN) through an IP
tunnel if:
‰ an end device is known to be attached to an access point on a
remote IP subnet.
‰ the frame type is configured to pass.
IP and ARP frames are only forwarded inbound through the IP tunnel if
the source IP address belongs to the root IP subnet. Usually, these
frames originate from wireless end devices that have roamed away from
their root IP subnet. Frames transmitted by servers or wired devices that
are connected to a remote IP subnet are not forwarded inbound
through IP tunnels if the IP address does not belong to the root IP
subnet.
MAC frames that are forwarded inbound are encapsulated by the access
point at the remote end of the IP tunnel, forwarded through the IP
tunnel to the root access point, unencapsulated, and placed on the
network.
Frame Types That Are Never Forwarded
Certain frame types are never forwarded through IP tunnels. Frame
types that are never forwarded include IP frames used for coordinating
routers and MAC frames used for coordinating bridges. Other frame
types that are never forwarded include:
‰ 802.1d bridge frames
‰ Proprietary VLAN switch frames
‰ IP frames with a broadcast or multicast Ethernet address
‰ IP frames with the following router protocol types and decimal
values:
— DGP (86) (Dissimilar Gateway Protocol)
— EGP (8) (Exterior Gateway Protocol)
— IDPR (35) (Inter-Domain Policy Routing Protocol)
— IDRP (45) (Inter-Domain Routing Protocol)