Re: Slightly OT: PfARGHHHHHHHH!

I realize that no user config is required for AS prepend but some ISP's
don't allow. I am more interested in the community prepend and what it will
take to make this happen. Thanks in advance for any assistance.

Marc

On Mon, Aug 20, 2012 at 4:45 PM, marc edwards <renorider_at_gmail.com> wrote:

> So what is this half baked product my SE sold me? The documentation looks
> good on Cisco's site and reads
>
> To enforce an entrance link selection, PfR offers the following methods:
> BGP Autonomous System Number Prepend
>
> After PfR selects a best entrance for an inside prefix, extra autonomous
> system hops (up to a maximum of six) are prepended to the inside prefix BGP
> advertisement over the other entrances. The extra autonomous system hops on
> the other entrances increase the probability that the best entrance will be
> used for the inside prefix. This is the default method PfR uses to control
> an inside prefix, and no user configuration is required.
> BGP Autonomous System Number Community Prepend
>
> After PfR selects a best entrance for an inside prefix, a BGP prepend
> community is attached to the inside prefix BGP advertisement from the
> network to another autonomous system such as an ISP. The BGP prepend
> community will increase the number of autonomous system hops in the
> advertisement of the inside prefix from the ISP to its peers. Autonomous
> system prepend BGP community is the preferred method to be used for PfR BGP
> inbound optimization because there is no risk of the local ISP filtering
> the extra autonomous system hops. There are some issues, for example, not
> all ISPs support the BGP prepend community, ISP policies may ignore or
> modify the autonomous system hops, and a transit ISP may filter the
> autonomous system path. If you use this method of inbound optimization and
> a change is made to an autonomous system, you must issue an outbound
> reconfiguration using the clear ip bgp command.
>
>
>
> http://www.cisco.com/en/US/docs/ios-xml/ios/pfr/configuration/15-1mt/pfr-bgp-inbound.html#GUID-52E6BAC0-FE00-43DD-BE37-822FC2ED5C0F
>
>
> This sounds great until I read further and find no configuration
> references to make this happen. Looking through all commands in
>
> http://www.cisco.com/en/US/docs/ios-xml/ios/pfr/command/pfr-cr-book.html
>
> I don't see anything either.
>
>
> Is this blatant false advertising or am I missing something?
>
>
> Regards,
>
> Marc

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Received on Mon Aug 20 2012 - 16:51:18 ART