Solved: spanning-tree portfast and switchport mode access

ada.chan · ‎10-03-2007

On a Cat 3560 IOS based switch, can someone please tell me the difference between:

int g0/1

switchport mode access

and

int g0/1

spanning-tree portfast?

Many thanks!

nambi_gct · ‎10-03-2007

"switchport mode access" command makes the port access port.It means that this port will be part of only one VLAN, which will be configured with "switchport access vlan x".If you do not use this command the port will be part of vlan 1.

"spanning-tree portfast" is an STP optimisation mechanism for access ports which immediately moves the port to Forwarding state to minimise the connectivity loss to the end host.And also if portfast enabled port flaps it wont generate TCN.

Hope this helps.

View solution in original post

nambi_gct · ‎10-03-2007

"switchport mode access" command makes the port access port.It means that this port will be part of only one VLAN, which will be configured with "switchport access vlan x".If you do not use this command the port will be part of vlan 1.

"spanning-tree portfast" is an STP optimisation mechanism for access ports which immediately moves the port to Forwarding state to minimise the connectivity loss to the end host.And also if portfast enabled port flaps it wont generate TCN.

Hope this helps.

ada.chan · ‎10-03-2007

No thats what I call a fast respnse! Thankyou.

Here I was thinking that they were essentially the same command! Thanks again!