Edge Ports And Point-To-Point Links; Port States - GE Multinet 4 Instruction Manual

CHAPTER 6: OPERATIONAL GUIDE
MULTINET4 MULTI-PORT SERIAL SERVER & MANAGED SWITCH – INSTRUCTION MANUAL
Port
Root: Each bridge (except the root bridge) has a single root port. This
is the port with the lowest root path cost (the best way to the
root.).
All traffic to and from the root bridge passes through the root
port of the designated bridge.
Designated: Each bridge (except the root bridge) has at least one designated
port. If only one port is connected to the segment it is the
designated port. If more than one port is connected to the
segment then the port with the best priority value in its ID is the
designated port for the segment.
Any port on the root bridge that is connected to a segment is a
designated port.
All Traffic to and from a specific segment passes through the
designated port of the designated bridge.
Backup: A port on a designated bridge that is connected to the same
segment as the designated port on that bridge. In the event of
failure in the designated port the backup port would become
the designated port. A backup port is blocked (inactive).
Alternate: A port that connects to a different segment than the root port
on the same bridge. An alternate port provides an alternate
path to the root that is inferior to the path provided by the root
port. In the event of failure in the root port the alternate port
would become the root port. An alternate port is blocked
(inactive).

6.3.1.4 Edge Ports and Point-to-Point Links

There are two other ways of classifying ports that can enable a quick transfer to the
forwarding state and thus faster convergence:
Edge Port – This is a port that connects directly to an end station. Since it connects to a
single host it is incapable of forming loops, so may be safely placed in a forwarding state
without going through the listening and learning stages.
Point-to-Point Links – When a port connects directly to another switch it can safely be
placed in forwarding mode.

6.3.1.5 Port States

The Multinet4 implementation of RSTP supports four operational states for a port:
Blocking – The port does not transmit or receive data frames, but the port does continue
to receive BPDUs.
Listening – The port can send and receive BPDUs, but it is not learning MAC addresses or
forwarding data frames.
Table 6–1: RSTP Port Roles
Role
OPERATIONAL GUIDE
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