Specifications

xStack DGS-3400 Series Layer 2 Gigabit Managed Switch CLI Manual
Example usage:
To set the Switch globally for the Multiple Spanning Tree Protocol (MSTP):
DGS-3400:4#config stp version mstp
Command: config stp version mstp
Success.
DGS-3400:4#
config stp
Purpose Used to setup STP, RSTP and MSTP on the Switch.
Syntax
config stp {maxage <value 6-40> | maxhops <value 1-20> | hellotime <1-10> |
forwarddelay <value 4-30> | txholdcount <value 1-10> | fbpdu [enable | disable]
| lbd [enable | disable] | lbd_recover_timer [<value 0> | <value 60 -1000000>]}
Description This command is used to setup the Spanning Tree Protocol (STP) for the entire
switch. All commands here will be implemented for the STP version that is currently
set on the Switch.
Parameters
maxage <value 6-40> − This value may be set to ensure that old information does
not endlessly circulate through redundant paths in the network, preventing the
effective propagation of the new information. Set by the Root Bridge, this value will
aid in determining that the Switch has spanning tree configuration values consistent
with other devices on the bridged LAN. If the value ages out and a BPDU has still not
been received from the Root Bridge, the Switch will start sending its own BPDU to all
other switches for permission to become the Root Bridge. If it turns out that your
switch has the lowest Bridge Identifier, it will become the Root Bridge. The user may
choose a time between 6 and 40 seconds. The default value is 20.
maxhops <value 1-20> - The number of hops between devices in a spanning tree
region before the BPDU (bridge protocol data unit) packet sent by the Switch will be
discarded. Each switch on the hop count will reduce the hop count by one until the
value reaches zero. The Switch will then discard the BDPU packet and the
information held for the port will age out. The user may set a hop count from 1 to 20.
The default is 20.
hellotime <value 1-10> − The user may set the time interval between transmission of
configuration messages by the root device in STP, or by the designated router in
RSTP, thus stating that the Switch is still functioning. A time between 1 and 10
seconds may be chosen, with a default setting of 2 seconds.
In MSTP, the spanning tree is configured by port and therefore, the
hellotime must be set using the configure stp ports command for switches utilizing
the Multiple Spanning Tree Protocol.
forwarddelay <value 4-30> − The maximum amount of time (in seconds) that the root
device will wait before changing states. The user may choose a time between 4 and
30 seconds. The default is 15 seconds.
txholdcount <value 1-10> - The maximum number of BDPU Hello packets transmitted
per interval. Default value = 3.
fbpdu [enable | disable] − Allows the forwarding of STP BPDU packets from other
network devices when STP is disabled on the Switch. The default is enable.
lbd [enable | disable] – When this is enabled, the Switch will temporarily block STP
switch-wide when a BDPU packet has been looped back. If the Switch detects its
own BDPU packet coming back, it signifies a loop on the network. STP will
automatically be blocked and an alert will be sent to the administrator. The default is
enable.
lbd_recover_timer [ 0 | < second 60 -1000000 > ] – Time allowed for recovery after
an STP loopback has been detected. After the timer has expired the Switch checks
for an STP loopback, if no loopback detected, STP will be resumed. Entering 0 will
disable LBD recovery.
Restrictions Only administrator-level users can issue this command.
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