mailing list archives
Re: Implementations/suggestions for Multihoming IPv6 for DSL sites
From: Luigi Iannone <luigi () net t-labs tu-berlin de>
Date: Tue, 19 Apr 2011 17:30:58 +0200
On Apr 18, 2011, at 10:09 PM, Owen DeLong wrote:
On Apr 18, 2011, at 12:18 PM, Jeff Wheeler wrote:
2011/4/18 Lukasz Bromirski <lukasz () bromirski net>:
LISP scales better, because with introduction of *location*
prefix, you're at the same time (or ideally you would)
withdraw the original aggregate prefix. And as no matter how
you count it, the number of *locations* will be somewhat
limited vs number of *PI* address spaces that everyone wants
I strongly disagree with the assumption that the number of
locations/sites would remain static. This is the basic issue that
many folks gloss over: dramatically decreasing the barrier-to-entry
for multi-homing or provider-independent addressing will, without
question, dramatically increase the number of multi-homed or
Done properly, a multi-homed end-site does not need to have
its own locator ID, but, could, instead, use the locator IDs of
all directly proximate Transit ASNs.
This is exactly what LISP suggests. Your locators are provided by your provider.
I don't know if LISP particularly facilitates this, but, I think it
would be possible generically in a Locator/ID based system.
LISP "solves" this problem by using the router's FIB as a
macro-flow-cache. That's good except that a site with a large number
of outgoing macro-flows (either because it's a busy site, responding
to an external DoS attack, or actually originating a DoS attack from a
compromised host) will cripple that site's ITR.
The closer you move the ITRs to the edge, the less of an issue this becomes.