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Re: policy routing and netflow (was Re: karl and paul, expostulating )

  • From: Alec H. Peterson
  • Date: Thu Feb 20 18:21:18 1997

On Feb 20, 1997, Brett D. Watson wrote:
> you better tell cisoc that then :) they call source based routing
> "policy routing".  bad choice of names i guess but that's what they
> call it.  it's an inbound route map applied to an interface and you
> look at the *source* address of the packet, then use various "set"
> clauses based on that address.

No, this is not source based _routing_, it's _filtering_.  _BIG_
difference.  The filters I speak of do examine the source address
(sometimes), but the decision of what interface to switch the packet
to is handled normally.  The only thing the filter does do is dictate
whether or not to allow the packet to be switched in the first place.

>   i have news for you, policy routing has nothing to do with 
> re-writing source or destination addresses.

You are correct, I misspoke on that count.  What I meant to say was
that access-list filters (using the access-group parameter) do not
control where the packet is switched, whereas policy routing does do

>   if you're filtering based on source-anything, and you're using a 
> cisco, i'd like to know how you're doing it without policy 
> route-maps.  please see:

I'm using extended access lists.  I'd be happy to show you if you'd

>   i didn't imply that you were doing anything.  i may have 
> misundestood justin but i thought he was implying that netflow 
> switching would increase the switching speed of policy based routing, 
> as cisco calls it, and it does not.  that's all i was getting at.

I think you need to re-examine what policy routing really is.  

>   yes it does.  i never said it didn't work well.  who's mail were 
> you reading anyway?

Yours.  I was just re-iterating how well it functioned.


|Alec Peterson - [email protected]    | Erols Internet Services, INC.        |
|Network Engineer                    | Springfield, VA.                     |
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