/27 the new /24

Jason Baugher jason at thebaughers.com
Fri Oct 2 16:47:31 UTC 2015


Are you suggesting that the Tier 1 and 2's that I connect to are not
filtering out anything shorter than /24? My expectation is that they are
dropping shorter than /24, just like I am.

Correct me if I'm wrong, but every *NOG BGP best practices document I've
read has advocated dropping all prefixes shorter than /24 at ingress and
egress.

On Fri, Oct 2, 2015 at 11:34 AM, William Herrin <bill at herrin.us> wrote:

> On Fri, Oct 2, 2015 at 11:55 AM, Suresh Ramasubramanian
> <ops.lists at gmail.com> wrote:
> > Besides which more than one provider filters by a minimum prefix length
> > per /8 - wasn't  Swisscom or someone similar doing that?  So multi
> > homing with even a /24 is somewhat patchy in terms of effectiveness
>
> Hi Suresh,
>
> That hasn't been true for something like a decade. Anybody who filters
> anything shorter than /24 without also taking a default route (or the
> equivalent) is not fully connected to the Internet.
>
> Regards,
> Bill Herrin
>
>
>
> --
> William Herrin ................ herrin at dirtside.com  bill at herrin.us
> Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>
>



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