Dell S4048T User Manual

Current root has priority 32768, Address 0001.e806.953e
Number of topology changes 2, last change occured 1d2h ago on Te 1/21
Port 374 (TenGigabitEthernet 1/21) is root Forwarding
Port path cost 20000, Port priority 128, Port Identifier 128.374
Designated root has priority 32768, address 0001.e806.953e
Designated bridge has priority 32768, address 0001.e806.953e
Designated port id is 128.374, designated path cost 20000
Number of transitions to forwarding state 1
BPDU (MRecords): sent 93671, received 46843
The port is not in the Edge port mode
Port 384 (TenGigabitEthernet 1/31) is
alternate Discarding
Port path cost 20000, Port priority 128, Port Identifier 128.384
Designated root has priority 32768, address 0001.e806.953e
Designated bridge has priority 32768, address 0001.e809.c24a
Designated port id is 128.384, designated path cost 20000
Number of transitions to forwarding state 1
BPDU (MRecords): sent 39291, received 7547
The port is not in the Edge port mode
Influencing MSTP Root Selection
MSTP determines the root bridge, but you can assign one bridge a lower priority to increase the probability
that it becomes the root bridge.
To change the bridge priority, use the following command.
• Assign a number as the bridge priority.
PROTOCOL MSTP mode
msti instance bridge-priority priority
A lower number increases the probability that the bridge becomes the root bridge.
The range is from 0 to 61440, in increments of 4096.
The default is 32768.
Example of Assigning and Verifying the Root Bridge Priority
By default, the simple configuration shown previously yields the same forwarding path for both MSTIs. The
following example shows how R3 is assigned bridge priority 0 for MSTI 2, which elects a different root bridge
than MSTI 2.
To view the bridge priority, use the show config command from PROTOCOL MSTP mode.
R3(conf-mstp)#msti 2 bridge-priority 0
1d2h51m: %RPM0-P:RP2 %SPANMGR-5-STP_ROOT_CHANGE: MSTP root changed for instance 2.
My
Bridge ID: 0:0001.e809.c24a Old Root: 32768:0001.e806.953e New Root:
0:0001.e809.c24a
R3(conf-mstp)#show config
!
protocol spanning-tree mstp
no disable
MSTI 1 VLAN 100
Multiple Spanning Tree Protocol (MSTP) 674

Dell S4048T Specifications

General

Switching Capacity	1.44 Tbps
Rack Units	1U
Form Factor	Rack-mountable
Power Device	Internal power supply
Power Redundancy	Optional
Product Type	Switch
Jumbo Frame Support	Yes
Routing Protocol	OSPF, BGP, RIP, VRRP, PIM-SM, IGMP
Remote Management Protocol	SNMP, RMON, Telnet, SSH
Features	Quality of Service (QoS), Jumbo Frames Support, Virtual Route Redundancy Protocol (VRRP), VLAN support, sFlow, Multiple Spanning Tree Protocol (MSTP), Rapid Spanning Tree Protocol (RSTP), IPv6 support
Compliant Standards	IEEE 802.3, IEEE 802.3u, IEEE 802.3ab, IEEE 802.3ae
Dimensions (W x D x H)	17.3 in x 16 in x 1.7 in
Operating Temperature	0°C to 40 °C
Operating Humidity	10% to 90% (non-condensing)