85、how docs MSTP maintain compatibility with RSTP?
RSTP IMPLEMENTS A TTL THAT IS COMPATIBLE WITH THE MSTP MAX AGE TIMER.
MSTP SUPPORTS FIVE PORT STATES IN THE SAME WAY AS RSTP.
MSTP SENDS ALL SPANNING-TREE INFORMATION IN ONE BPDU.
RSTP ENCODES REGION INFORMATION FROM AN MSTP BPDU INTO A SINGLE INSTANCE.
