STP Max Age
The Max Age is a value contained within BPDUs which are used by the Spanning Tree Protocol (STP). The full contents of a BPDU can be found here: STP contents of a BPDU.
The Max Age value has two functions:
- It indicates the age in seconds at which time the current BPDU should be discarded. By default, this value is set to 20 but can be anything from 1 to 40.
- It acts as a maximum value for the Message Age parameter in the BPDU.
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