Implementations/suggestions for Multihoming IPv6 for DSL sites
Owen DeLong
owen at delong.com
Mon Apr 11 13:37:41 UTC 2011
On Apr 11, 2011, at 6:30 AM, Luigi Iannone wrote:
>
> On 11, Apr, 2011, at 15:17 , Owen DeLong wrote:
>
> [snip]
>>>>
>>>> Doing IPv4 LISP on any kind of scale requires significant additional prefixes which at this time doesn't seem so practical to me.
>>>
>>> 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.
>>>
>>> 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.
>>>
>>> Luigi
>>>
>> Who said anything about BGP? I was talking about the amount of additional IP space needed vs. the
>> amount of IPv4 free space remaining.
>>
>
> Sorry. I misunderstood.
>
> But can you explain better? Why should LISP require more IP space than normal IPv4 deployment?
>
> If you are a new site, you ask for an IP block. This is independent from whether or not you will use LISP.
>
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?
>
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?
>
Or perhaps the complexity of LISP in the details still confuses me, despite people's insistence
that it is not complex.
Owen
> thanks
>
> Luigi
>
>
>
>> Owen
>>
>
More information about the NANOG
mailing list