Re: portfast

From: Stephen Sprunk (ssprunk@cisco.com)
Date: Sat Jul 07 2001 - 21:37:26 EDT


Thus spake "Christopher Neill" <noise@cow.org>
> i don't see the point of running STP on any port that's attached to a
single
> host. i only run it for the ports connected to my routers, hubs, CSS,
PIX,
> trunks to other switches..
>
> am i missing something or is this kinda the dog chasing his tail?

At least on Cisco products, you can't disable STP on a per-port basis --
it's per-vlan. While STP loop protection is rather feeble in the face
of malice, I pity the support staff of a network without it.

Portfast does work very well, and was in fact designed specifically due
to a new generation of Intel chips which could get all the way through
boot and Novell GNS timeout before STP got to forwarding -- the Mac
problem came much later, and I've never even seen the Windows problem
mentioned here.

The wide applicability of this should be evident in the "set port host"
command in CatOS, which enables portfast any many other similar things
which should always be set for hosts. That this isn't default is, I
believe, a relic of Cisco's compliance with the 802.1D spec.

S



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