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STP Part I. STP or Spanning Tree Protocol is used to stop loops in a switched Network. STP is also called 802.1D BPDU: Bridge protocol data unit are just like signals which switches send to detect the loops every 2 secs .
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STP Part I • STP or Spanning Tree Protocol is used to stop loops in a switched Network. • STP is also called 802.1D • BPDU: • Bridge protocol data unit are just like signals which switches send to detect the loops every 2 secs. • BPDU also help to find the Root Bridge in a Network also called as CORE Switch • Election of Root Bridge depends upon two things , the priority and mac address. Default priority is 32768. Increment or decrement with 4096. Lower priority & Lower MAC address is better to become Root Bridge. • Usually older switches are chosen by default as Root Bridges because of their Lower MAC address (Need Caution)
STP Part I Once the Switch becomes a Root Bridge, it will never block its ports and are called forwarding portsor best known as Designated ports. Note: Designated ports are available on each switch one per link. Between Lower & Higher MAC address switch port, Higher will be blocked. Once the Root Bridge is selected. Switches try to find the best shortest path to reach the Root Bridge and block all redundant or unnecessary links. The ports used to reach the Root Bridge are called Root Ports. Note: Switch with Root Ports are not Root Bridge, as the ports are used to reach the Root Bridge. They use link cost to find the best possible shortest path to reach the Root Bridge Lower Bridge ID (priority + mac) is very important in choosing the path.
STP Part I Link Cost Table: LINK BANDWIDTH COST 4Mbps 250 10Mbps 100 16Mbps 62 45Mbps 39 100 Mbps 19 155Mbps 14 622Mbps 6 1Gbps 4 10Gbps 2
STP Part I STP Part II coming soon !! Enjoy Thanks, Hyp3ri0n www.itpings.com www.linuxworld.co