Intel ER8100STUS - Express 8100 Router, Reference Manual

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Reference.bok : Chapter10 115 Wed Apr 22 10:58:08 1998
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Bridge Spoofing
WAN Bridging Services
Bridge Spoofing on a
Designated Port
When Bridge Spoofing is set up on a Designated Port, the link only forwards con-
figuration BPDU packets when the contents of the configuration BPDU packets
changes, that is, when the topology of the bridged network changes or is being
established. When the contents of a configuration BPDU packet changes, config-
uration BPDU packets are sent over the WAN link until a valid acknowledge is
received from the non-designated port on the bridge over the WAN link.
Bridge Spoofing on a
non-designated port
When Bridge Spoofing is set up for a non-designated port, the bridge does not
expect configuration BPDU packets from the non-designated port. The bridge
continues to send the last configuration BPDU packet it received at the intervals
defined by the Hello Time in the Root Bridge, to bridges connected on Designat-
ed Ports to maintain the integrity of the bridged network.
Non-BPDU Spoofing
Bridge Spoofing on a
WAN link
Another feature of Bridge Spoofing is when two bridge ports are connected via
a WAN link and one port is in the Blocking State and the other is in the Forward-
ing State. Normally, Non-BPDU packets are sent from the Forwarding Port and
are Discarded by the Blocking Port—this is a waste of valuable WAN resources.
When Bridge Spoofing is enabled on the bridges, no Non-BPDU packets (of any
type) are forwarded to a Blocking Port.
Enabling Bridge Spoofing
When can Bridge
Spoofing be used
Bridge Spoofing can only be used between two Intel Express 8100 Routers.
Bridge Spoofing cannot be used on WAN links connected to routers/bridges
from other manufacturers.
Requirements for use Bridge Spoofing must be set up at both the routers on either side of a WAN link.
for satisfactory operation.
Enabling Bridge
Spoofing
Bridge Spoofing is set up when setting up bridging services for a WAN link, on
the
Advanced
screen.
Note
Bridge Spoofing is enabled by default for WAN links. When communi-
cating with a bridge which does not support Bridge Spoofing, for
example a bridge from another manufacturer, Bridge Spoofing must be
disabled.