Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Spannig Tree Portfast

Hi All

Should I configure on the interfaces

spanning-tree portfast to hubs and switches when these are connected to our main switch?

Thanks

2 ACCEPTED SOLUTIONS

Accepted Solutions
Purple

Re: Spannig Tree Portfast

No you never enable portfast on links attached to other network devices , this is only used on client access ports. Network device links should have portfast turned "off".

Cisco Employee

Re: Spannig Tree Portfast

Hi Friend,

Actually yes anything which can give an access and connection to multiple connections/nodes and then loop back to the same switch is a risk.

HTH

Ankur

*Pls rate all helpfull post

5 REPLIES
Purple

Re: Spannig Tree Portfast

No you never enable portfast on links attached to other network devices , this is only used on client access ports. Network device links should have portfast turned "off".

Cisco Employee

Re: Spannig Tree Portfast

Hi Friend,

It is never recommended and doing this you are risking a STP loop.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12240se/scg1/swstpopt.htm#wp1031116

HTH

Ankur

*Pls rate all helpfull post

New Member

Re: Spannig Tree Portfast

Thanks Guys

Even if these hubs and switches are not intelligent and they are passive hubs and switches?.

Thanks

Cisco Employee

Re: Spannig Tree Portfast

Hi Friend,

Actually yes anything which can give an access and connection to multiple connections/nodes and then loop back to the same switch is a risk.

HTH

Ankur

*Pls rate all helpfull post

Re: Spannig Tree Portfast

I agree with all of the above. As usual, those are high level rules to avoid shooting yourself in the foot. The most important point is that there must be no loop introduced by the L2 device to which you're connecting your portfast port. In fact, I would not hesitate using portfast to a hub where only end stations are connected;-) (doing so to a switch would be much more controversial but potentially not impossible either).

Regards,

Francois

218
Views
0
Helpful
5
Replies
CreatePlease login to create content