we have two cisco slm2024 switches and one 3com (also supports stp and portfast configuration) 24 port switch
we have 4 servers all connected using gig to the 3com switch
all the workstation, servers and printers are connected to a combination of all three switches
to my understanding connecting workstations and servers to portfast enabled ports will help with connectivity and faster connect time
currently the three switches are conected via cat6 cables i understand i should not enable portfast on these ports because it can create looping is this correct.
my direct question is
i would only enable portfast on the ports which have a server or a computer connected to them? and nothing else
The portfast feature basically tells the switch ONLY host devices will be attached to this interface and as a result the stp can be bypassed and the interface can be put straight into a forwarding state.
So in summary portfast = end users/servers/printers etc.. - anything but hubs or switches.
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Most of it is added by Pdriver, just to make one note irrespective of switches the concept of Portfast remains the same.
The simple explanation is that PortFast will immediately transition a port to the forwarding state and not attempt to detect a switching loop unless a BPDU is received on the port with PortFast enabled. So plugging in multiple links on hubs, switches or bridges to the network can temporary switching loops.
Another major advantage of PortFast is that a TCN (Topology Change Notification) is not generated by spanning-tree each time a port goes up or down. This conserves resources as spanning-tree does not have to reprocess the tree every time a TCN is generated.