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Spanning-Tree

having difficulties comprehending pieces of stp. can someone expand a bit on CST vs. 802.1d From my understanding 802.1d utilizes 1-to-1 of STP instance per VLAN where CST has one instance for all VLAN's.

Any further info would be appreciated.

thankyou

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Blue

Re: Spanning-Tree

802.1d is the IEEE spanning-tree algorithm that prevents loops in a layer 2 network.

CST is an implmentation of 802.1d where there is only one instance of STP running for all the vlans in your layer 2 network no matter how many vlans that is.

PVST/PVST+ is an implementation of 802.1d where each vlan runs it's own instance of STP.

Jon

2 REPLIES

Re: Spanning-Tree

Hi

CST is common spanning-tree is a dot1q standard which maintain a single instance of STP for all the vlans.

802.1d is a ieee standard of STP.

Thanks

Mahmood

Hall of Fame Super Blue

Re: Spanning-Tree

802.1d is the IEEE spanning-tree algorithm that prevents loops in a layer 2 network.

CST is an implmentation of 802.1d where there is only one instance of STP running for all the vlans in your layer 2 network no matter how many vlans that is.

PVST/PVST+ is an implementation of 802.1d where each vlan runs it's own instance of STP.

Jon

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