stpPortOptfRootLoopGuard 1.3.6.1.4.1.3320.9.253.7.1.5

Root Guard prevents a port that is receiving superior BPDUs from becoming root port. In SSTP and PVST modes, if a Root Guard-enabled port is receiving superior BPDUs, it is always blocked. In RSTP and MSTP modes, if a Root Guard-enabled port originally didn't receive superior BPDUs, but now it is receiving superior BPUDs, it is blocked. Loop guard prevents alternate and root ports from becoming designated ports. In SSTP and PVST modes, if a Loop guard-enabled port is designated port, it is always blocked. In RSTP and MSTP modes, if a Loop guard-enabled port becomes designated port because of a failure that can't receive BPDUs, it is blocked.