Connectivity Guide

Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
----------------------------------------------------------------------
ethernet1/1/5 128.276 128 500 FWD 0 24577 90b1.1cf4.a523 128.276
ethernet1/1/6 128.280 128 500 LRN 0 24577 90b1.1cf4.a523 128.280
Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
-------------------------------------------------------------
ethernet1/1/5 Desg 128.276 128 500 FWD 0 AUTO No
ethernet1/1/6 Desg 128.280 128 500 LRN 0 AUTO No
Loop guard
To congure loop guard on an interface:
• Enable loop guard on a per-port or port-channel interface in INTERFACE mode.
spanning-tree guard {loop | root | none}
– loop — Enables loop guard on an interface.
– root — Enables root on an interface.
– none — Enables the guard mode to none.
• Disable loop guard on a port or port-channel interface in INTERFACE mode.
no spanning-tree guard loop
Port enabled with loop guard conditions
• Loop guard is supported on any STP-enabled port or port-channel interface in RPVST+ mode.
• You cannot enable root guard and loop guard at the same time on an STP port. The loop guard conguration overwrites an existing root
guard conguration and vice versa.
• Enabling BPDU guard and loop guard at the same time on a port results in a port that remains in the Blocking state and prevents trac
from owing through it. For example, when you congure both Portfast BPDU guard and loop guard:
– If a BPDU is received from a remote device, BPDU guard places the port in the Err-Disabled Blocking state and no trac forwards
on the port.
– If no BPDU is received from a remote device which was sending BPDUs, loop guard places the port in the Loop-Inconsistent
Blocking state and no trac forwards on the port.
• When used in a PVST+ network, STP loop guard performs per-port or per port-channel at a VLAN level. If no BPDUs are received on a
port-channel interface, the port or port-channel transitions to a Loop-Inconsistent or Blocking state only for this VLAN.
Global parameters
All non-root bridges accept the timer values on the root bridge.
Forward-time
Amount of time required for an interface to transition from the Discarding state to the Learning state or from the
Learning state to the Forwarding state.
Hello-time Time interval within which the bridge sends BPDUs.
Max-age Length of time the bridge maintains conguration information before it refreshes information by recomputing the
RPVST+ topology.
• Modify the forward-time in seconds in CONFIGURATION mode, from 4 to 30, default 15.
spanning-tree vlan vlan-id forward-time seconds
• Modify the hello-time in seconds in CONFIGURATION mode, from 1 to 10, default 2. With large congurations involving more numbers
of ports, Dell EMC recommends increasing the hello-time.
spanning-tree vlan vlan-id hello-time seconds
Layer 2
343