ipv4/25s and above

Joe Maimon jmaimon at jmaimon.com
Thu Nov 17 17:55:07 UTC 2022



Mark Tinka wrote:
>
> For our DIA/Enterprise business, we offer customers a /30 for p2p 
> link, and a /29 as initial standard for onward assignment within their 
> LAN.

You could instead use a /31. Or private/enterprise-private or unnumbered 
and route them the single /32 to use for their NAT on say a loopback 
interface. And the /29 ? I would reserve it but not assign it without a 
formal request.
>
> Interestingly, most customers will NAT on the p2p address space, and 
> barely use the onward assignment. In such cases, link migrations cause 
> issues, because customers bake their internal configurations against 
> those p2p IP addresses, which are pegged to specific edge routers on 
> our side that can't move due to our need to minimize the iBGP 
> footprint in the network. It's not a major issue in absolute terms, 
> but a headache nonetheless.
>
See above.

> We can offer customers up to a /24 maximum (i.e., we will let the /29 
> expand into a /24), and no more. 

Either you have lots of fallow ground or very few customers. I dont see 
how this strategy would work elsewhere.

> If they need more than a /24, time to speak to AFRINIC.
>
> We don't charge for address space. Our Sales people want us to, but we 
> don't feel it makes sense. It's not a big-enough deterrent for us to 
> keep IPv4 stock. And when we do run out of IPv4 space, it will be like 
> having billions of $$ on a deserted island.
>
> Mark.
>
Your sales people are right. Since you can deliver quite usable service 
that enables them to operate just as they have before with a single /32, 
and with technical advantages to yourself, all the extra wasted integers 
should be bringing in value.

And since its quite nice to assign a loopback to every CPE anyways, two 
birds, one stone. Carry that in your iBGP.

Best,

Joe



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