User`s manual

NPort 6000 Series User’s Manual Module Settings
6-2
NM-TX01, NM-TX02, NM-FX01-M-SC, NM-FX01-S-SC,
NM-FX02-M-SC, NM-FX02-S-SC
Redundancy Settings
This section applies to NPort 6000 server’s that have the NM-TX01 module installed. From the
left navigation panel, click Network Settings Æ Module to configure Redundancy Settings.
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. NPort 6000’s STP feature is disabled by default.
To be completely effective, you must enable RSTP/STP on every NPort 6000 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:
The topology of a bridged network will be determined much more quickly compared to STP.
RSTP is backward compatible with STP, making it relatively easy to deploy. For example:
• Defaults to sending 802.1D style BPDUs if packets with this format are received.
• STP (802.1D) and RSTP (802.1w) can operate on different ports of the same NPort 6000. This
feature is particularly helpful when NPort 6000 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.
What is STP?
STP (802.1D) is a bridge-based system that is used to implement parallel paths for network traffic.
STP uses a loop-detection process to:
• Locate and then disable less efficient paths (i.e., paths that have a lower bandwidth).
• Enable one of the less efficient paths if the most efficient path fails.