RSTP or VSTP Forced to Run as IEEE 802.1D STP
On MX Series routers in a Layer 2 environment, you can force the configured Rapid Spanning-Tree Protocol (RSTP) or VLAN Spanning-Tree Protocol (VSTP) to run as the original IEEE 802.1D Spanning-Tree Protocol (STP) version. Configure this option for compatibility with older bridges that do not support RSTP or VSTP:
Keep the following limitations in mind when RSTP or VSTP are run as the original STP version:
- If you configure an instance interface as an edge port, the configuration statement is ignored.
- If you configure point-to-point link mode for an instance interface, the configuration statement is ignored.
To force RSTP or VSTP to run as the IEEE 802.1D version, include the following statement:
force-version stp;
You can include this statement at the following hierarchy levels:
- [edit protocols rstp]
- [edit protocols vstp]
- [edit routing-instances routing-instance-name protocols rstp]
- [edit routing-instances routing-instance-name protocols vstp]

