[c-nsp] Lot of input errors on a NPE-G1 interface

[Chris Gotstein]

%Warning: portfast should only be enabled on ports connected to a single 
host. Connecting hubs, concentrators,  switches, bridges, etc… to this 
interface  when portfast is enabled, can cause temporary bridging loops.

My understanding of this was a router would be included as well since 
it's used to connect multiple hosts.  I only enable portfast on ports 
connected to end-user devices.  I don't see a good reason to enable it 
on ports connected to routers, but that's just how it was explained to 
me, I very well could be wrong.

On 5/23/2012 1:29 PM, Gert Doering wrote:
> Hi,
>
> On Wed, May 23, 2012 at 01:15:16PM -0500, Chris Gotstein wrote:
>> It's probably not going to address the overrun issue, but from a best
>> practices stand point, it should not be enabled on interfaces that
>> connected to other connected devices, ie a router or switch.
>
> Uh, so it should only be turned on for switchports that connect to...
> "no device"?
>
> Anyway: right for "to switch", dead wrong for "to router".  It should be
> turned on for any connection that is known to not go to a switch or hub,
> and doubly so if rapid-pvstp is used (due to TCNs being sent on a link
> flap otherwise, possibly causing stalls elsewhere).
>
> As far as a switch is concerned, a "router" is the same thing as "a host" -
> it doesn't forward layer2 things, so can't cause a routing loop.
>
> gert
>

-- 
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Chris Gotstein, Network Engineer, U.P. Logon/Computer Connection U.P.
http://uplogon.com | +1 906 774 4847 | chris at uplogon.com