There are lots of transits that will take le 32 on their customers inbound but filter le 24 on egress announcements.
On Fri, Oct 2, 2015 at 12:47 PM, Jason Baugher <ja...@thebaughers.com> wrote: > 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 <b...@herrin.us> wrote: > > > On Fri, Oct 2, 2015 at 11:55 AM, Suresh Ramasubramanian > > <ops.li...@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 ................ her...@dirtside.com b...@herrin.us > > Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/> > > > -- [stillwa...@gmail.com ~]$ cat .signature cat: .signature: No such file or directory [stillwa...@gmail.com ~]$
