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icnd2:spanning-tree [2024/04/23 09:11]
114.119.130.33 old revision restored (2023/10/15 15:12)
icnd2:spanning-tree [2024/05/14 17:02] (current)
3.23.102.216 old revision restored (2024/04/28 06:17)
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 =====CONCEPT===== =====CONCEPT=====
-  * It does this with Each Switch broadcasting a **''HELLO BPDU''**, made up of that SW's **''Priority + MAC''**. Default Priority is 32768. The SW with the **''lowest BPDU''** (superior) is elected the ROOT BRIDGE.  +  * It does this with Each Switch broadcasting a **''HELLO BPDU''**, made up of that SW's **''Priority + MAC''**. Default Priority is 32768. The SW with the lowest **''BPDU''** (superior) is elected the ROOT BRIDGE.  
-  * Each SW will then determine a **''ROOT PORT''**, one per SW. A **''DESIGNATED''** port is then elected on each segment.  +  * Each SW will then determine a ROOT PORT, one per SW. A DESIGNATED port is then elected on each segment. There can only be one DESIGNATED port per SEGMENT/LINK.  
-  * There can only be **one DESIGNATED port per SEGMENT/LINK. ** +  * Any port that is not DESIGNATED or a ROOT port, is then set to a BLOCKING state. 
-  * Any port that is **not** **''DESIGNATED''** or a **''ROOT''** port, is then set to a **''BLOCKING''** state. +Note that once a ROOT Bridge is elected, all other bridges will only forward HELLO BPDU's originating from the ROOT BRIDGE. The Root cost is incremented as the HELLO BPDU is received (COST=$COST+$PORT_COST). The Root Cost starts off @ 0 from the ROOT. Each subsequent Bridge tacks on it's COST TO THE ROOT BRIDGE as it is **received**.
-Note that once a ROOT Bridge is elected, all other bridges will only forward HELLO BPDU'**originating** from the **''ROOT BRIDGE''**. The Root cost is incremented as the **''HELLO BPDU''** is **received (COST=$COST+$PORT_COST)**. The Root Cost **starts off @ 0** from the **''ROOT''**. Each subsequent Bridge tacks on it'**COST TO THE ROOT BRIDGE** as it is **received**. +
- +
-=====Root Port Election===== +
-SW1 <> SW2 (Fa0/11-> Fa0/11, Fa0/12 -> Fa0/12) +
  
  
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   * --COST IS SAME: Is my my Bridge ID lower?   * --COST IS SAME: Is my my Bridge ID lower?
   * --if NO to either, PORT WILL BE BLOCKED!   * --if NO to either, PORT WILL BE BLOCKED!
- 
-==PORT COSTS== 
-  * **10Mb link:** **''100''** 
-  * **100Mb link:** **''19''** 
-  * **1Gb Link:** **''4''** 
  
 =====COMMANDS:===== =====COMMANDS:=====
icnd2/spanning-tree.1713863498.txt.gz · Last modified: 2024/04/23 09:11 by 114.119.130.33