[139500] in North American Network Operators' Group
Re: Implementations/suggestions for Multihoming IPv6 for DSL sites
daemon@ATHENA.MIT.EDU (Owen DeLong)
Mon Apr 11 09:44:37 2011
From: Owen DeLong <owen@delong.com>
In-Reply-To: <8353E89E-90A2-4F08-A774-D8CE24A98066@net.t-labs.tu-berlin.de>
Date: Mon, 11 Apr 2011 06:37:41 -0700
To: Luigi Iannone <luigi@net.t-labs.tu-berlin.de>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Apr 11, 2011, at 6:30 AM, Luigi Iannone wrote:
>=20
> On 11, Apr, 2011, at 15:17 , Owen DeLong wrote:
>=20
> [snip]
>>>>=20
>>>> Doing IPv4 LISP on any kind of scale requires significant =
additional prefixes which at this time doesn't seem so practical to me.
>>>=20
>>> This is not accurate IMO. To inject prefixes in the BGP is needed =
only to make non-LISP sites talk to LISP sites. Even there you can =
aggressively aggregate, as explained in draft-ietf-lisp-interworking.
>>>=20
>>> As long as the LISP deployment progress you can even withdraw some =
prefixes from the BGP infrastructure and advertise only a larger =
aggregate in order for legacy site to reach the new LISP site.
>>>=20
>>> Luigi
>>>=20
>> Who said anything about BGP? I was talking about the amount of =
additional IP space needed vs. the
>> amount of IPv4 free space remaining.
>>=20
>=20
> Sorry. I misunderstood.=20
>=20
> But can you explain better? Why should LISP require more IP space than =
normal IPv4 deployment?
>=20
> If you are a new site, you ask for an IP block. This is independent =
from whether or not you will use LISP.
>=20
Sure, but, if you also need locators, don't you need additional IP space =
to use for locators?
> If you are an existing site and you want to switch to LISP why you =
need more space? you can re-use what you have?
>=20
Perhaps I misunderstand LISP, but, I though you needed space to use for =
locators and space
to use for IDs if you are an independently routed multi-homed site.
If you are not an independently routed multi-homed site, then, don't you =
need a set of host IDs
to go with each of your upstream locators?
As I understand LISP, it's basically a dynamic tunneling system where =
you have two discrete,
but non-overlapping address spaces, one inside the tunnels and one =
outside.
If that's the case, then, I believe it leads to at least some amount of =
duplicate consumption of
IP numbers.
> Or I missed the point again?
>=20
Or perhaps the complexity of LISP in the details still confuses me, =
despite people's insistence
that it is not complex.
Owen
> thanks=20
>=20
> Luigi
>=20
>=20
>=20
>> Owen
>>=20
>=20
