Spanning Tree Options: Rstp (802.1W) And Stp (802.1D); Rstp (802.1W); Stp (802.1D) - HP ProCurve Series 4100GL Management And Configuration Manual

802.1w Rapid Spanning Tree Protocol (RSTP) and 802.1d Spanning Tree Protocol (STP)

Spanning Tree Options: RSTP (802.1w) and STP (802.1D)

14-6
Spanning Tree Options: RSTP (802.1w)
and STP (802.1D)

RSTP (802.1w)

The IEEE 802.1D version of spanning tree (STP) can take a fairly long time to
resolve all the possible paths and to select the most efficient path through the
network. The IEEE 802.1w Rapid Reconfiguration Spanning Tree (RSTP)
significantly reduces the amount of time it takes to establish the network path.
The result is reduced network downtime and improved network robustness.
In addition to faster network reconfiguration, RSTP also implements greater
ranges for port path costs to accommodate the higher and higher connection
speeds that are being implemented.
RSTP is designed to be compatible with IEEE 802.1D STP, and HP recom­
mends that you employ it in your network. For more information, refer to
"Transitioning from STP to RSTP" on page 14-8.

STP (802.1D)

The IEEE 802.1D version of spanning tree has been in wide use and can coexist
in a network in which RSTP (802.1w) has been introduced. if your network
currently uses 802.1D STP and you are not yet ready to implement RSTP, you
can apply STP to the switch until such time as you are ready to move ahead
with RSTP. STP offers the full range of STP features found in earlier product
releases, including:
STP Fast Mode for Overcoming Server Access Failures: If an end
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node is configured to automatically access a server, the duration of the
STP startup sequence can result in a "server access failure". On ports
where this is a problem, configuring STP Fast Mode can eliminate the
failure. For more information, see "STP Fast Mode" on page 14-25. The
next sections describe how to configure STP on the switch. For more
information on STP operation, see "How Spanning Tree Operates" on page
14-4.
Fast-Uplink STP for Improving the Recovery (Convergence) Time
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in Wiring Closet Switches with Redundant Uplinks: This means that
a switch having redundant links toward the root device can decrease the