[139516] in North American Network Operators' Group
Re: Implementations/suggestions for Multihoming IPv6 for DSL sites
daemon@ATHENA.MIT.EDU (Luigi Iannone)
Mon Apr 11 11:16:19 2011
From: Luigi Iannone <luigi@net.t-labs.tu-berlin.de>
In-Reply-To: <0E79A6C8-E45A-4EC8-92C3-EC7993EF6C4B@delong.com>
Date: Mon, 11 Apr 2011 17:15:59 +0200
To: Owen DeLong <owen@delong.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 11, Apr, 2011, at 15:37 , Owen DeLong wrote:
>=20
> On Apr 11, 2011, at 6:30 AM, Luigi Iannone wrote:
>=20
>>=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?
No, those are the IP address that you provider gives to your border =
router.
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>> 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.
Not exactly. You do not need more space. You re-use what you have.=20
>=20
> 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?
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> 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.
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> If that's the case, then, I believe it leads to at least some amount =
of duplicate consumption of
> IP numbers.
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No true. I ask for a PI block that I will use as EID-Prefix, then the =
locators are part of the address space of my providers.
There is no duplication.
>> 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.
>=20
IMHO it is very simple. As any new technology there is just a learning =
curve to follow, but for LISP it is not steep ;-)
Luigi
> Owen
>=20
>> thanks=20
>>=20
>> Luigi
>>=20
>>=20
>>=20
>>> Owen
>>>=20
>>=20
>=20
