3com 5500-SI Manual Do Utilizador
RSTP Configuration 547
After the STP protocol is enabled, the modification of any parameter will result in the
re-calculation of the spanning tree on the Switch. It is therefore recommended to
configure all the RSTP parameters before enabling the STP feature on the Switch and
the port.
re-calculation of the spanning tree on the Switch. It is therefore recommended to
configure all the RSTP parameters before enabling the STP feature on the Switch and
the port.
Enable/Disable RSTP on
a Switch
You can use the following command to enable RSTP on the Switch.
Perform the following configurations in System View.
Table 596 Enable/Disable RSTP on a Device
Only after the RSTP is enabled on the Switch can other configurations take effect.
By default, RSTP is enabled.
Enable/Disable RSTP on
a Port
You can use the following command to enable/disable the RSTP on the designated
port. To flexibly control the RSTP operations, after RSTP is enabled on the Ethernet
ports of the Switch, it can be disabled again to prevent the ports from participating in
the spanning tree calculation.
port. To flexibly control the RSTP operations, after RSTP is enabled on the Ethernet
ports of the Switch, it can be disabled again to prevent the ports from participating in
the spanning tree calculation.
Specify the
maximum
transmission
rate of STP
packets on a
port
maximum
transmission
rate of STP
packets on a
port
No Ethernet pot can
send more than 3 STP
packets within one
Hello Time.
send more than 3 STP
packets within one
Hello Time.
The more STP packets a port sends within
one Hello Time, the more resources are
consumed. It is therefore recommended to
limit the transmission rate of STP packets
on a port, preferably to the default value.
one Hello Time, the more resources are
consumed. It is therefore recommended to
limit the transmission rate of STP packets
on a port, preferably to the default value.
Specify the
preference of a
port
preference of a
port
All Ethernet ports are
at the preference
128.
at the preference
128.
The port preference plays an important role
in root port selection. You can make a port
to be root port by giving it a smallest
preference value.
in root port selection. You can make a port
to be root port by giving it a smallest
preference value.
Configure
whether to
connect a port
with a
peer-to-peer link
whether to
connect a port
with a
peer-to-peer link
RSTP can detect
automatically
whether the current
Ethernet port is
connect to a
peer-to-peer link.
automatically
whether the current
Ethernet port is
connect to a
peer-to-peer link.
The two ports connected with a
peer-to-peer link can rapidly transit to the
forwarding status by sending synchronous
packets, eliminating unnecessary
forwarding delay.
peer-to-peer link can rapidly transit to the
forwarding status by sending synchronous
packets, eliminating unnecessary
forwarding delay.
Specify the Path
Cost on a port
Cost on a port
Specify the
standard to
follow in Path
Cost calculation
standard to
follow in Path
Cost calculation
The Switch gets the
path cost of a port
from the link rate
under the IEEE 802.1t
standard.
path cost of a port
from the link rate
under the IEEE 802.1t
standard.
The path cost of a port is closely related to
the transmission rate of the link the port
connected with. The larger the link rate is,
the smaller the path cost shall be. It is
recommended to use the default
configuration.
the transmission rate of the link the port
connected with. The larger the link rate is,
the smaller the path cost shall be. It is
recommended to use the default
configuration.
Configure
whether a port
can be an Edge
Port
whether a port
can be an Edge
Port
All Ethernet ports are
configured as
non-edge ports.
configured as
non-edge ports.
For ports directly connected with terminals,
please configure them as edge ports, and
enable the BPDU protection function on
them.
please configure them as edge ports, and
enable the BPDU protection function on
them.
Specify mCheck
for a port
for a port
-
You can change the operational mode of a
port from STP-compatible to RSTP.
port from STP-compatible to RSTP.
Configure the
protection
functions on a
Switch
protection
functions on a
Switch
No protection
function is enabled
on a Switch.
function is enabled
on a Switch.
It is recommended to enable the BPDU
protection function on the Switches directly
connected with user PCs.
protection function on the Switches directly
connected with user PCs.
Table 595 RSTP Configuration (continued)
Device
Configuration Default Value
Note
Operation
Command
Enable/Disable RSTP on a device
stp { enable | disable }
Restore RSTP to the default value
undo stp