Implementations/suggestions for Multihoming IPv6 for DSL sites

Luigi Iannone luigi at
Tue Apr 12 08:52:10 UTC 2011

On 11, Apr, 2011, at 17:26 , Owen DeLong wrote:

>>>> 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?
>> No, those are the IP address that you provider gives to your border router.
> Right... In addition to my provider independent addresses... That's more address space than is required
> if I am not using LISP.

No, you just use the IP addresses of the interface to your upstream as "locators". 
Those addresses are there anyway, right?
So using LISP is not adding anything.

>> 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.
> Right... Ordinarily, without LISP, I get a PI block and use that for EID and the routing is based on the
> EID prefix. With LISP, the EID prefix is PI and I use additional PA resources to do the routing locators.
> That's what I meant by duplication. There are additional PA resources required on top of the PI in order
> to make LISP work.

I still do not see this duplication (may be I need more coffee this morning..)
You do not need to modify anything in the PA space of your provider. Those resources are there and are used to make your block reachable also without LISP. 


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