RPVST with VSX guidelines

  • Path cost is not allowed to be configured on the ISL port.

  • Layer 2 link connected parallel to ISL link is blocked by RPVST.

  • Do not configure port-specific spanning tree configurations on the ISL.

  • Topology changes for VSX LAGs are accounted on the active multichassis LAG role only.

  • RPVST is supported in both VSX and non-VSX environments.

  • The common bridge ID continues to be used even after the VSX split brain scenario is identified.

  • STP configurations on VSX LAG ports must be the same on VSX switches.

  • RPVST interoperates with IEEE xSTP BPDU only when VLAN 1 is assigned to a trunk interface or configured with a native VLAN for all layer 2 ports on the RPVST switch. VLAN 1 is assigned to a trunk interface by entering the vlan trunk allowed [<VLAN-LIST> | all] command.

  • Maximum supported RPVST instances that can be configured.

    • 832x series switches: 64

    • 8400 series switches: 254