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 >> >
