STP Max Age


The Message Age is a value contained within [BPDUs](/stp-bpdu-types) which are used by the [Spanning Tree Protocol (STP)](/spanning-tree-protocol-stp).  The full contents of a BPDU can be found here: [STP contents of a BPDU](/stp-contents-of-a-bpdu).

The Message Age is a value found within BPDUs that starts off at 0 when it is sent from the root bridge, and is incremented by one every time it passes through a non-root bridge. Once the Message Age reaches the [Max Age](/stp-max-age) value, the BPDU is discarded. It works kind of like a TTL found in IP packets, to prevent BPDUs from being relayed forever in a topology.


Links:


https://community.cisco.com/t5/switching/msg-age-and-max-age-in-rstp/td-p/2251614

https://forum.networklessons.com/t/rapid-spanning-tree-configuration/1139/21?u=lagapides

STP Message Age

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STP Message Age

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