Why Portfast participate in STP
If I understand Portfast is used so that Computers will receive DHCP configuration ASAP, and for the port to skip blocking , learning, listening phases.
however if portfast is configured without other XXXGUARD configuration, then if a switch is plugged to the port it can cause a Loop.
I wonder why Cisco design it that way ?
it makes sense to tell a port that you are configured to only talk to computers and not to switches...just like Access port but with skipping blocking , learning, listening phases
Any comments on this ?
Thanks
however if portfast is configured without other XXXGUARD configuration, then if a switch is plugged to the port it can cause a Loop.
I wonder why Cisco design it that way ?
it makes sense to tell a port that you are configured to only talk to computers and not to switches...just like Access port but with skipping blocking , learning, listening phases
Any comments on this ?
Thanks
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Don.
1 - Perfect design, is to tell the port you are accepting only "Workstation", no switches. how to do that ?
However if I am not wrong :
2 -- If you configure a port as access port, you plug a workstation, you are fine. If you plug a Switch, then topology change will kick in, and nowadays , there are Blades and probably even ESX hosts that have Virtual switches, and their NIC is already configured as Trunk or listens to BPDUs, and if you plug it to an Access Port it will cause Topology Change.
3-- Portfast (According to what I have read) will prevent Topology change only if you configure it with BPDU Guard.
I wonder if it is guaranteed that there will be no Topology change or Loop.
What I am looking for is Bullet 1 to be fulfilled with skipping "Blocking,Listening,Learni
== I also need to understand the difference between Loop and Topology change
Topology change is when switches start election of the Root Bridge, but if we have Root bridges(Primary and Secondary) already hard-coded then Topology change should not occur.
*Loop , if I understand , STP is already on the Switch by default, it can block redundant ports, so why Loop should happen in this case.?
1 - Perfect design, is to tell the port you are accepting only "Workstation", no switches. how to do that ?
However if I am not wrong :
2 -- If you configure a port as access port, you plug a workstation, you are fine. If you plug a Switch, then topology change will kick in, and nowadays , there are Blades and probably even ESX hosts that have Virtual switches, and their NIC is already configured as Trunk or listens to BPDUs, and if you plug it to an Access Port it will cause Topology Change.
3-- Portfast (According to what I have read) will prevent Topology change only if you configure it with BPDU Guard.
I wonder if it is guaranteed that there will be no Topology change or Loop.
What I am looking for is Bullet 1 to be fulfilled with skipping "Blocking,Listening,Learni
== I also need to understand the difference between Loop and Topology change
Topology change is when switches start election of the Root Bridge, but if we have Root bridges(Primary and Secondary) already hard-coded then Topology change should not occur.
*Loop , if I understand , STP is already on the Switch by default, it can block redundant ports, so why Loop should happen in this case.?
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Thank you for now..I am still reading about if a question comes up I will post it.
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Since we know that it is conceived for a host to be plugged into it why would it receives or sends BPDUs at first place...
You see what I mean ?