3 Replies Latest reply: Dec 10, 2019 8:01 AM by Juergen Ilse CCNA R&S RSS

    CCENt Question


      How are MAC addresses removed from a MAC address table?


      A. They are removed automatically if they remain inactive for the duration of the switch aging timer.
      B. They are removed automatically on a FIFO basis when the address-table limit has been reached.
      C. They must be manually cleared from the table.
      D. They are removed automatically if they remain inactive for the duration of the global MAC address timer.


      Answer: D


      Why not A ????

      in the official guide book P 161 " The switch times out any entries whose timer reaches the defined aging time "


      Thanks for your help

        • 1. Re: CCENt Question

          A or D, D sounds better; what does book call  this aging timer?  i think answer is D based on proper Cisco name for this MAC aging timer[

          it is globally configured-able on switch; not per vlan or port, or specific mac,  the mac address aging time is a command global (from global config mode) that applies to all MACs  

          • 2. Re: CCENt Question
            Steven Davidson

            Poorly written question/answer choice combination in my opinion.  It doesn't accurately measure knowledge.  The important thing is to know that mac addresses age out of the table regardless of how one might word it.  It'd be nice to see this style of question purged from the exams.

            • 3. Re: CCENt Question
              Juergen Ilse CCNA R&S

              I totally agree. This is a very poor written question, because nobody is really interested, how that timer is called. The important knowledge is only, that this timer exists, and MAC-address entries, that were not used for the time given by that timer, will be deleted from the MAC-address table automatically.