ProCurve 2610-PWR Technical Information download pdf (Page 120)

Spanning-Tree Operation

Configuring Rapid Reconfiguration Spanning Tree (RSTP)

Transitioning from STP to RSTP

IEEE 802.1w RSTP is designed to be compatible with IEEE 802.1D STP. Even

if all the other devices in your network are using STP, you can enable RSTP

on your switch, and even using the default configuration values, your switch

will interoperate effectively with the STP devices. If any of the switch ports

are connected to switches or bridges on your network that do not support

RSTP, RSTP can still be used on this switch. RSTP automatically detects when

the switch ports are connected to non-RSTP devices in the spanning tree and

communicates with those devices using 802.1D STP BPDU packets.

Because RSTP is so much more efficient at establishing the network path,

though, that it is highly recommended that all your network devices be

updated to support RSTP. RSTP offers convergence times of less than one

second under optimal circumstances. To make the best use of RSTP and

achieve the fastest possible convergence times, though, there are some

changes that you should make to the RSTP default configuration. See “Opti-

mizing the RSTP Configuration” below, for more information on these

changes.

Note Under some circumstances, it is possible for the rapid state transitions

employed by RSTP to result in an increase in the rates of frame duplication

and misordering in the switched LAN. In order to allow RSTP switches to

support applications and protocols that may be sensitive to frame duplication

and misordering, setting the Force Protocol Version parameter to stp-compat-

ible allows RSTP to be operated with the rapid transitions disabled. The value

of this parameter applies to all ports on the switch. See the information on

Force Version on page 5-16.

As indicated above, one of the benefits of RSTP is the implementation of a

larger range of port path costs, which accommodates higher network speeds.

New default values have also been implemented for the path costs associated

with the different network speeds. This can create some incompatibility

between devices running the older 802.1D STP and your switch running RSTP.

Please see the “Note on Path Cost” on page 5-19 for more information on

adjusting to this incompatibility.

5-12

1 2 ... 115 116 117 118 119 120 121 122 123 124 125 ... 363 364

No comments

ProCurve 2610-PWR Technical Information Page 120