Reference Guide

ethernet1/1/6 128.280 128 500 BLK 0 32768 3417.4455.667f 128.150
Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
------------------------------------------------------------------
ethernet1/1/5 Root 128.276 128 500 FWD 0 AUTO No
ethernet1/1/6 Altr 128.280 128 500 BLK 0 AUTO No
Interface parameters
Adjust two interface parameters to increase or decrease the likelihood that a port becomes a forwarding port.
Port cost Value that is based on the interface type. The greater the port cost, the less likely the port is selected to be a
forwarding port.
Port priority Inuences the likelihood that a port is selected to be a forwarding port if several ports have the same port cost.
Default values for port cost by interface:
• 100-Mb/s Ethernet interfaces — 200000
• 1-Gigabit Ethernet interfaces — 20000
• 10-Gigabit Ethernet interfaces — 2000
• Port-channel with 100 Mb/s Ethernet interfaces — 180000
• Port-channel with 1-Gigabit Ethernet interfaces — 18000
• Port-channel with 10-Gigabit Ethernet interfaces — 1800
1 Change the port cost of an interface in INTERFACE mode (0 to 200000000).
spanning-tree msti number cost cost
2 Change the port priority of an interface in INTERFACE mode (0 to 240 in increments of 16, default 128).
spanning-tree msti number priority priority
View MSTi interface conguration
OS10(conf-if-eth1/1/7)# do show spanning-tree msti 0 interface ethernet 1/1/7
ethernet1/1/7 of MSTI 0 is Designated Forwarding
Edge port: No (default)
Link type: point-to-point (auto)
Boundary: Yes, Bpdu-filter: Disable, Bpdu-Guard: Disable, Shutdown-on-Bpdu-Guard-violation: No
Root-Guard: Disable, Loop-Guard: Disable
Bpdus (MRecords) Sent: 69, Received: 0
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
----------------------------------------------------------------------
ethernet1/1/7 0.284 0 1 FWD 0 32768 90b1.1cf4.9b8a 0.284
Forward trac
EdgePort allows the interface to forward trac approximately 30 seconds sooner as it skips the Blocking and Learning states. The
spanning-tree bpduguard enable command causes the interface hardware to shut down when it receives a BPDU.
CAUTION
: Congure EdgePort only on links connecting to an end station. EdgePort can cause loops if you enable it on an
interface connected to a network.
When you implement BPDU guard, although the interface is placed in Error Disabled state when receiving the BPDU, the physical interface
remains in the Up state. The hardware discards regular network trac after a BPDU violation. BPDUs are forwarded to the CPU, where
they are discarded as well.
• Enable EdgePort on an interface in INTERFACE mode.
spanning-tree port type edge
Layer 2
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