Optimizations and enhancements to the IEEE RSTP 802.1W implementation

Abstract

In an embodiment, aA method for supporting dynamic configuration changes,includes:comprises receiving a message from a current root bridge;, comparing thea bridge media access control (MAC) address of a receiving port to thea bridge MAC address of the received message;, if the bridge MAC addresses are not the same, then comparing a current priority value to with a previous priority value of the current root bridge; if the current priority value is inferior, then, determining if the port receiving the message port is a qualified root port;, and if the port is a qualified root port, then returning a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change an RSTP calculation.

1. A method comprising:
 at a network device configured to perform a bridging function, examining a message comprising a first bridge media access control (MAC) address of a current root bridge; 
 if the first bridge MAC addresses and a second bridge MAC address currently held by a receiving port of the network device are not the same, then comparing a current priority value to a previous priority value of the current root bridge; 
 if the current priority value is inferior to the previous priority value, then determining if the port receiving the message is a qualified root port; and 
 if the port is a qualified root port, then returning a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       2. The method of  claim 1  wherein the message is a bridge protocol data unit (BPDU) packet. 
     
     
       3. A network device comprising:
 a memory; and 
 a state machine configured to: 
 examine a message comprising a first bridge media access control (MAC) address of a current root bridge; 
 if the first bridge MAC address and a second bridge MAC address currently held by a receiving port of the network device are not the same, then compare a current priority value to a previous priority value of the current root bridge; 
 if the current priority value is inferior to the previous priority value, then determine if the port receiving the message is a qualified root port; and 
 if the port is a qualified root port, then return a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       4. The network device of  claim 3  wherein the message is a bridge protocol data unit (BPDU) packet. 
     
     
       5. An article of manufacture, comprising:
 a machine-readable medium having stored thereon instructions to: 
 examine a message comprising a first bridge media access control (MAC) address of a current root bridge; 
 if the first bridge MAC address and a second bridge MAC address currently held by a receiving port of the network device are not the same, then compare a current priority value to a previous priority value of the current root bridge; 
 if the current priority value is inferior to the previous priority value, then determine if the port receiving the message is a qualified root port; and 
 if the port is a qualified root port, then return a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       6. An apparatus comprising:
 means for, at a network device configured to perform a bridging function, examining a message comprising a first bridge media access control (MAC) address of a current root bridge; 
 means for, if the first bridge MAC address and a second bridge MAC address currently held by a receiving port of the network device are not the same, then comparing a current priority value to a previous priority value of the current root bridge; 
 means for, if the current priority value is inferior to the previous priority value, then determining if the port receiving the message is a qualified root port; and 
 means for, if the port is a qualified root port, then returning a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       7. A method comprising:
 at a network device configured to perform a bridging function, examining a message comprising a first bridge address of a current root bridge; 
 if the first bridge address and a second bridge address currently held by a receiving port of the network device are not the same, then comparing a current priority value to a previous priority value of the current root bridge; 
 if the current priority value is inferior to the previous priority value, then determining if the port receiving the message is a qualified root port; and 
 if the port is a qualified root port, then returning a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       8. The method of  claim 7  wherein the message is a bridge protocol data unit (BPDU) packet. 
     
     
       9. A network device comprising:
 a memory; and 
 a state machine configured to: 
 examine a message comprising a first bridge address of a current root bridge; 
 if the first bridge address and a second bridge address currently held by a receiving port of the network device are not the same, then compare a current priority value to a previous priority value of the current root bridge; 
 if the current priority value is inferior to the previous priority value, then determine if the port receiving the message is a qualified root port; and 
 if the port is a qualified root port, then return a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       10. The network device of  claim 9  wherein the message is a bridge protocol data unit (BPDU) packet. 
     
     
       11. An article of manufacture, comprising:
 a machine-readable medium having stored thereon instructions to: 
 examine a message comprising a first bridge address of a current root bridge; 
 if the first bridge address and a second bridge address currently held by a receiving port of the network device are not the same, then compare a current priority value to a previous priority value of the current root bridge; 
 if the current priority value is inferior to the previous priority value, then determine if the port receiving the message is a qualified root port; and 
 if the port is a qualified root port, then return a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change. 
 
     
     
       12. An apparatus comprising:
 means for, at a network device configured to perform a bridging function, examining a message comprising a first bridge address of a current root bridge; 
 means for, if the first bridge address and a second bridge address currently held by a receiving port of the network device are not the same, then comparing a current priority value to a previous priority value of the current root bridge; 
 means for, if the current priority value is inferior to the previous priority value, then determining if the port receiving the message is a qualified root port; and 
 means for, if the port is a qualified root port, then returning a superior designated message to permit each bridge to execute a rapid spanning tree calculation for use in a dynamic configuration change.