Users Guide

EdgePort
EdgePort allows the interface to forward traffic approximately 30 seconds sooner as it skips the Blocking and Learning states.
CAUTION: Configure EdgePort only on links connecting to an end station. EdgePort can cause loops if you enable it on
an interface connected to a network. Edge ports do not receive BPDUs.
• Enable EdgePort on an interface in INTERFACE mode.
spanning-tree port type edge
Configure EdgePort
OS10(conf-if-eth1/1/4)# spanning-tree port type edge
View interface status
OS10# show spanning-tree interface ethernet 1/1/4
ethernet1/1/4 of MSTI 0 is designated Forwarding
Edge port:yes port guard :none (default)
Link type is point-to-point (auto)
Boundary: YES bpdu filter :disable bpdu guard :disable bpduguard shutdown-on-
violation :disable RootGuard: disable LoopGuard disable
Bpdus (MRecords) sent 610, received 5
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
--------------------------------------------------------------------------
ethernet1/1/4 128.272 128 500 FWD 0 32768 90b1.1cf4.a911 128.272
==========================================================================
Spanning-tree extensions
STP extensions provide a means to ensure efficient network convergence by securely enforcing the active network topology. OS10
supports BPDU filtering, BPDU guard, root guard, and loop guard STP extensions.
The system discards regular data traffic after a BPDU violation.
BPDU filtering
Protects the network from unexpected flooding of BPDUs from an faulty device. Enabling BPDU Filtering on an
interface causes the system to send or receive BPDUs.
BPDU guard Blocks the L2 bridged ports and LAG ports connected to end hosts and servers from receiving any BPDUs. When
you enable BPDU guard, it places the bridge or LAG port in the Error_Disable or Blocking state if the port receives
any BPDU frames. In case of a LAG, all member ports, are placed in the Blocking state. The data traffic is dropped
but the port continues to forward BPDUs to the CPU that are later dropped. To prevent further reception of
BPDUs, configure a port to shut down using the
violation action command. For more information on STP
commands, see STP Commands.
Root guard Avoids bridging loops and preserves the root bridge position during network transitions. STP selects the root
bridge with the lowest priority value. During network transitions, another bridge with a lower priority may attempt
to become the root bridge and cause unpredictable network behavior. To avoid such an attempt and preserve the
position of the root bridge, configure the spanning-tree guard root command. Root guard is enabled on
ports that are designated ports. The root guard configuration applies to all VLANs configured on the port.
Loop guard Prevents L2 forwarding loops caused by a cable or interface hardware failure. When a hardware failure occurs, a
participating spanning-tree link becomes unidirectional and a port stops receiving BPDUs. When a blocked port
stops receiving BPDUs, it transitions to a Forwarding state causing spanning-tree loops in the network. Enable
loop guard on a port that transitions to the Loop-Inconsistent state until it receives BPDUs using the spanning-
tree guard loop command. After BPDUs are received, the port moves out of the Loop-Inconsistent or
blocking state and transitions to an appropriate state determined by STP. Enabling loop guard on a per-port basis
enables it on all VLANs configured on the port. If you disable loop guard on a port, it moves to the Listening state.
NOTE:
1. Root guard and Loop guard are mutually exclusive.
2. Configuring one overwrites the other from the active configuration.
418 Layer 2