IPv4 Router Alert Option

Fri May 23 19:29:55 UTC 2008

Ron Bonica <rbonica at juniper.net> writes:

> Folks,
>
> It is my belief that many ISPs, will not accept datagrams containing the
> Router Alert IP option from customers. Do I have that right?

I think that in general, it is safe to say that most folks who run
Internet backbones do not care what options you have on IP packets and
are not filtering anyway.  Heck, I've never encountered anything
beyond unicast RPF in terms of SP filtering, and even *that* is not
especially prevalent.  If he's reading, Dave Katz will probably be
disappointed to hear that I couldn't even remember what that option
did without referring to RFC2113.

> I am asking so that I might better evaluate Internet drafts that would
> require ISPs to accept such packets.

Do these drafts actually exist, or are they merely hypothetical?

                                        ---rob