Page 228

188

Chapter 5

Using Spanning Tree with VLANs

Table 5.1 shows the different parameters available with the

set

spantree

command and their definitions.

T A B L E 5 . 1

set spantree

Parameters

Parameter

Definition

root

Designation to change the switch to the root
switch. The

set spantree root

command

changes the bridge priority from 32768
to 8192.

secondary

Designation to change the switch to a sec-
ondary root switch if the primary fails. This
automatically changes the bridge priority
from a default of 32768 to 16384.

VLAN_List

Optional command that changes the STP
parameters on a specified VLAN. If no VLAN
is specified, then it changes only VLAN 1 by
default. You can change the parameters for
VLANs 11005.

dia <network diameter>

Another optional command that specifies the
maximum number of bridges between any
two points where end stations attach. You
can set these parameters from 2 to 7. Figure
the network diameter by starting at the root
bridge and counting the number of bridges in
the VLAN. The root bridge is 1, so if you have
only one more switch, set the network diam-
eter to 2. This changes the timers in the VLAN
to reflect the new diameter.

hello <hello time>

Optional command that specifies in seconds
the duration between configuration mes-
sages from the root switch. You can set this
anywhere from 1 to 10 seconds (2 is the
default).

www.sybex.com