Re: Interesting BFD discussion on reddit

[Hugo Slabbert <hugo () slabnet com>]

> Because BFD packets can get routed across multiple hops. Unlike EBGP where
> you connect to a peer in a different AS and you have a direct connection,
> BFD packets can traverse multiple hops to reach the endpoint.

Then what's this "multihop" knob I have available in my BGP config?  Again, 
as Rob pointed out, "can" vs. "should" is a good consideration here, but 
unless I'm missing something both EBGP and BFD "can" do multihop...so...?

--
Hugo

On Tue 2015-Feb-17 07:42:20 +0530, Dave Waters <davewaters1970 () gmail com> wrote:

> Because BFD packets can get routed across multiple hops. Unlike EBGP where
> you connect to a peer in a different AS and you have a direct connection,
> BFD packets can traverse multiple hops to reach the endpoint.
>
> In case of multihop BFD the BFD packets also get re-routed when the
> topology changes so you can almost never bet on the TTL value to secure the
> protocol.
>
> Dave
>
> On Tue, Feb 17, 2015 at 7:03 AM, Rob Seastrom <rs () seastrom com> wrote:
>
> > Dave Waters <davewaters1970 () gmail com> writes:
> >
> > >
> > http://www.reddit.com/r/networking/comments/2vxj9u/very_elegant_and_a_simple_way_to_secure_bfd/
> > >
> > > Authentication mechanisms defined for IGPs cannot be used to protect BFD
> > > since the rate at which packets are processed in BFD is very high.
> > >
> > > Dave
> >
> > One might profitably ask why BFD wasn't designed to take advantage of
> > high-TTL-shadowing, a la draft-gill-btsh.
> >
> > -r

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