From: Alan Simpkins (alan_simpkins@xxxxxxxxx)
Date: Tue Sep 19 2000 - 12:36:38 GMT-3
However then Netflow switching does become an option assuming the
appropriate hardware.
Kevin Baumgartner <kbaumgar@cisco.com> wrote:
No that isn't exactly what I am saying. If you are running fast
switching
on a interface and then for example apply a access-list that does
tcp ports
filtering you are in effect turning off fast switching. This is
because
the router has to look into each packet as it goes in or out of
this
interface. So you can't fast switch the packet in this case.
Kevin
>
> Kevin,
> Are you saying that fast switching causes access-lists to be
bypassed or
> were you getting at something different?
> Thanks,
> George
>
> At 06:44 PM 9/13/00 -0700, Kevin Baumgartner wrote:
> >
> >All this does is to allow enabling of fast switch
> >or by doing "no ip route-cache" to disable fast switch and
> >doing process switching.
> >
> > The issue is that some features will not allow fast switching.
> >For example access-lists. The router need to look into each
packet
> >to see if there is match on the access-list. So in this case
fast switching
> >can't be used.
> >
> >With fast switching it looks at the first packet and then
> >finds out what interface to send it to. Then all other packets
who destination
> >is the same address will be fast switched out to the same
interface and
> >will no have to look in the packet at all. This is much faster
than
> >process switching.
> >
> > Also a quick troubleshooting thing to try if
> >packets are not going out a interface is to turn
> >off fast switching. Especially if you are try some new
> >features and then don't work.
> >
> > Kevin
> >
> >At 08:05 PM 9/13/00 -0500, you wrote:
> >
> >>Hi,
> >>
> >>Can anyone help me out here?
> >>
> >>I've been wondering about the aforementioned command. I
realize, after
> >looking at the docs that "ip route-cache" enables fast switch
processing but
> >I'm curious about the parameters and the ability to disable it.
> >>
> >>Can anyone provide me with some solid, factual, reasons as to
why you would
> >want to turn fast switching off or turn autonomous switching on,
etc? Also
> >why can you use it on a Vlan interface in a switch - this one
sort of has me
> >at the moment?
> >>
> >>If this is something basic that I'm overlooking.......well....I
was going
> >to apologize but we all have to take a trip back to the basics
sometime dont
> >we.....so I wont :)
> >>
> >>Thanks
> >>
> >>Jamie
> >
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