Virtual Private LAN Services
7210 SAS-X, R6 OS Services Guide Page 249
improvement and transitions conform to 802.1w in 30 seconds (both modes implement
fast convergence over point-to-point links).
• In the RSTP mode, the transmitted BPDUs contain the port's designated priority vector
(DPV) (conforms to 802.1D-2004). Older implementations may be confused by the DPV
in a BPDU and may fail to recognize an agreement BPDU correctly. This would result in
a slow transition to a forwarding state (30 seconds). For this reason, in the comp-dot1w
mode, these BPDUs contain the port's port priority vector (conforms to 802.1w).
The 7210 SAS supports BDPU encapsulation formats, and can dynamically switch between the
following supported formats (on a per-SAP basis):
• IEEE 802.1D STP
• Cisco PVST