aads renumbering rumor and implications
howland at Priss.com
Mon Jan 25 17:31:24 UTC 1999
The issue of reverse DNS is the only reason for having
"unique" exchange point addressing.
The fact as I see it is that the exchange point is not
a destination. The exchange point addresses are used solely
as a transit "space", and it's nice to know what you're
The only time that the exchange point as routable space
has been and issue for me is when reachability to those
network blocks is being readvertized by a peer.
There is NO reason that a service provider needs to
readvertise an exchange point network block. It's not a
destination. Eliminating this specific abuse would be a
Since there is no technical reason for an exchange point
to be routable, it comes down to whim. I *like* having
unique exchange point addresses for troubleshooting
purposes, for all the reasons below. That does not mean
it's not perfectly reasonable for an exchange point
operator to make it non-routable addressing, since it's
their exchange point.
If it weren't for the RA's, the ATM environment has no
need to be a shared network anyway. Might as well make the
VC's individually numbered /30's, or 10.254.254.0/24.
On Sun, Jan 24, 1999 at 09:35:13PM -0800, Randy Bush wrote:
> >> o does anyone see why the exchange address space needs to be globally
> >> routable?
> > Traceroute.
> as the fabric is used for peering under bi-lats, if we each announce the
> mesh to our customers and not to our peers, then i believe you will have
> your tracroutes and yet the prefix does not have to be globally routable,
> e.g. could be 209.666.42/24.
Holdon, i don't even see the need for that; if you traceroute out, the
packets will cross the exchange irregardless of whether you're announcing
it to your customers, and a message of TTL exceeded will be generated
from the exchange's address.. The important question is, should they
be globally UNIQUE for troubleshooting purposes? I think so.
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