Configures the ports in the specified STPD (Spanning Tree Domain) as auto, broadcast, edge, or point-to-point link types.
| stpd_name | Specifies an STPD name on the switch. |
| auto | Specifies the switch to automatically determine the port link type. An auto link behaves like a point-to-point link if the link is in full-duplex mode or if link aggregation is enabled on the port. Used for 802.1w configurations. |
| broadcast | Specifies a port attached to a LAN segment with more than two bridges. Used for 802.1D configurations. A port with broadcast link type cannot participate in rapid reconfiguration using RSTP or MSTP (Multiple Spanning Tree Protocol). By default, all STP.1D ports are broadcast links. |
| point-to-point | Specifies a port attached to a LAN segment with only two bridges. A port with point-to-point link type can participate in rapid reconfiguration. Used for 802.1w and MSTP configurations. By default, all 802.1w and MSTP ports are point-to-point link types. |
| port_list | Specifies one or more ports or slots and ports. |
| edge | Specifies a port that does not have a bridge attached. An edge port is placed and held in the STP (Spanning Tree Protocol) forwarding state unless a BPDU is received by the port. Used for 802.1w and MSTP configurations. |
| edge-safeguard | Specifies that the edge port be configured with edge safeguard, a loop prevention and detection mechanism. Used for 802.1w and MSTP configurations. |
| enable | Specifies that edge safeguard be enabled on the edge port(s). |
| disable | Specifies that edge safeguard be disabled on the edge port(s). |
| bpdu-restrict | Disables port as soon as a BPDU is received. |
| recovery-timeout | Time after which the port will be re-enabled. |
| seconds | Specifies the time in seconds. The range is 60 to 600. The default is 300. |
STP.1D ports are broadcast link types 802.1w and MSTP ports are auto link types.
If your STPD has the same name as another component, for example a VLAN (Virtual LAN), we recommend that you specify the identifying keyword as well as the name. If your STPD has a name unique only to that STPD, the keyword stpd is optional.
The default, broadcast links, supports legacy STP (802.1D) configurations. If the switch operates in 802.1D mode, any configured port link type will behave the same as the broadcast link type.
RSTP rapidly moves the designated ports of a point-to-point link type into the forwarding state. This behavior is supported by RSTP and MSTP only.
In an MSTP environment, configure the same link types for the CIST and all MSTIs.
An auto link behaves like a point-to-point link if the link is in full duplex mode or if link aggregation is enabled on the port; otherwise, an auto link behaves like a broadcast link. If a non-STP switch exists between several switches operating in 802.1w mode with auto links, the non-STP switch may negotiate full-duplex even though the broadcast domain extends over several STP devices.
RSTP does not send any BPDUs from an edge port nor does it generate topology change events when an edge port changes its state.
If you configure a port to be an edge port, the port immediately enters the forwarding state. Edge ports remain in the forwarding state unless the port receives a BPDU. In that case, edge ports enter the blocking state. The edge port remains in the blocking state until it stops receiving BPDUs and the message age timer expires.
Loop prevention and detection on an edge port configured for RSTP or MSTP is called edge safeguard. You configure edge safeguard on RSTP or MSTP edge ports to prevent accidental or deliberate misconfigurations (loops) resulting from connecting two edge ports together or by connecting a hub or other non-STP switch to an edge port. Edge safeguard also limits the impact of broadcast storms that might occur on edge ports.
An edge port configured with edge safeguard immediately enters the forwarding state and transmits BPDUs. This advanced loop prevention mechanism improves network resiliency but does not interfere with the rapid convergence of edge ports.
Recovery time starts as soon as the port becomes disabled. If no recovery-timeout is specified, the port is permanently disabled.
BPDU restrict can be disabled using the configure stpd stpd_name ports bpdu-restrict disableport_list command.
If edge safeguard is disabled, BPDU restrict is also disabled.
To configure a port as an edge port and enable edge safeguard on that port, use the configure stpd stpd_name ports link-type edgeport_list edge-safeguard command and specify enable.
To disable edge safeguard on the edge port, use the configure stpd stpd_name ports link-type edgeport_list edge-safeguard command and specify disable.
Two other commands are also available to enable and disable edge safeguard:
configure stpd ports edge-safeguard enableIn MSTP, configuring edge safeguard at CIST will be inherited in all MSTI (Multiple Spanning Tree Instances).
The following command configures slot 2, ports 1 through 4 to be point-to-point links in STPD s1:
configure stpd s1 ports link-type point-to-point 2:1-2:4
The following command enables edge safeguard on the RSTP edge port on slot 2, port 3 in STPD s1 configured for RSTP:
configure stpd s1 ports link-type edge 2:3 edge-safeguard enable
This command was first available in ExtremeXOS 10.1.
The BPDU Restrict function was added in ExtremeXOS 12.4.
This command is available on the Summit X450-G2, X460-G2, X670-G2, X770, and ExtremeSwitching X440-G2, X590, X620, X690, X870 series switches.
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