EDS-728 Series User’s Manual
Featured Functions
3-29
Enable Ring Coupling
Setting
Description
Factory Default
Enable
Select this EDS-728 as Coupler
Disable
Do not select this EDS-728 as
Coupler
Not checked
Coupling Mode
Setting
Description
Factory Default
Dual Homing
Select this item to change to the
Dual Homing configuration page.
Primary Port: not defined**
Backup Port: not defined**
Ring Coupling
(backup)
Select this item to change to the
Ring Coupling (backup)
configuration page.
Coupling Port: not defined**
Ring Coupling
(primary)
Select this item to change to the
Ring Coupling (primary)
configuration page
Coupling Port: not defined**
Primary/Backup Port
Setting
Description
Factory Default
Primary Port
Select any port of the EDS-728 to
be the primary ports.
not defined**
Backup Port
Select any port of the EDS-728 to
be the backup port.
not defined**
**You should manual adjust this port into another available port before enabling the architecture.
The STP/RSTP Concept
Spanning Tree Protocol (STP) was designed to help reduce link failures in a network, and provide
protection from loops. Networks that have a complicated architecture are prone to broadcast
storms caused by unintended loops in the network. The EDS-728’s STP feature is disabled by
default. To be completely effective, you must enable RSTP/STP on every EDS-728 connected to
your network.
Rapid Spanning Tree Protocol (RSTP) implements the Spanning Tree Algorithm and Protocol
defined by IEEE Std 802.1w-2001. RSTP provides the following benefits:
y
The topology of a bridged network will be determined much more quickly compared to STP.
y
RSTP is backward compatible with STP, making it relatively easy to deploy. For example:
¾
Defaults to sending 802.1D style BPDUs if packets with this format are received.
¾
STP (802.1D) and RSTP (802.1w) can operate on different ports of the same EDS-728.
This feature is particularly helpful when the EDS-728’s ports connect to older equipment,
such as legacy switches.
You get essentially the same functionality with RSTP and STP. To see how the two systems differ,
see the
Differences between RSTP and STP
section in this chapter.
NOTE
The STP protocol is part of the IEEE Std 802.1D, 1998 Edition bridge specification. The
explanation given below uses bridge instead of switch.
