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STP listening state - MAC address removal
daan5000
Member Posts: 34 ■■■□□□□□□□
in CCNA & CCENT
Hello community
I'm studying for ICND2 and have some trouble understanding the function of the STP listening port state.
What I understand is that a port that was previously in blocking state and then enters listening state will listen for BPDU messages and will not forward any frames during the time it is in listening state.
However, the book also notes that during this state, the switch will time out old "stale" mac address-entries. I'm not very sure what this means. First of all (I'm not sure if its related) the aging time of the mac address-table is by default 300 seconds, while listening state only takes 15 seconds. How does the switch determine which mac address entries are removed and which ones are kept? And second, which MAC addresses are removed? I suppose it's the MAC addresses that were learned on the failed port (before it failed)?
A good article about this is also welcome (couldn't find one myself).
Thank you for clearing this out.
I'm studying for ICND2 and have some trouble understanding the function of the STP listening port state.
What I understand is that a port that was previously in blocking state and then enters listening state will listen for BPDU messages and will not forward any frames during the time it is in listening state.
However, the book also notes that during this state, the switch will time out old "stale" mac address-entries. I'm not very sure what this means. First of all (I'm not sure if its related) the aging time of the mac address-table is by default 300 seconds, while listening state only takes 15 seconds. How does the switch determine which mac address entries are removed and which ones are kept? And second, which MAC addresses are removed? I suppose it's the MAC addresses that were learned on the failed port (before it failed)?
A good article about this is also welcome (couldn't find one myself).
Thank you for clearing this out.
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