Dell S4048T User Manual

To keep both ports in a Forwarding state, use extend system ID. Extend system ID augments the bridge ID
with a VLAN ID to differentiate BPDUs on each VLAN so that PVST+ does not detect a loop and both ports
can remain in a Forwarding state.
Figure 111. PVST+ with Extend System ID
• Augment the bridge ID with the VLAN ID.
PROTOCOL PVST mode
extend system-id
Example of Viewing the Extend System ID in a PVST+ Configuration
Dell(conf-pvst)#do show spanning-tree pvst vlan 5 brief
VLAN 5
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32773, Address 0001.e832.73f7
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32773 (priority 32768
sys-id-ext 5), Address 0001.e832.73f7
We are the root of Vlan 5
Configured hello time 2, max age 20, forward delay 15
PVST+ Sample Configurations
The following examples provide the running configurations for the topology shown in the previous
illustration.
Example of PVST+ Configuration (R1)
interface TenGigabitEthernet 1/22
no ip address
switchport
no shutdown
!
Per-VLAN Spanning Tree Plus (PVST+) 829

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)