CGNAT

Wed Feb 24 02:10:58 UTC 2021

> On Feb 22, 2021, at 6:44 AM, nanog at jima.us wrote:
> 
> While I don't doubt the accuracy of Lee's presentation at the time, at least two base factors have changed since then:
> 
> - Greater deployment of IPv6 content (necessitating less CGN capacity per user)

This is only true if the ISP in question is implementing IPv6 along side their CGN deployment and only if they get a significant uptake of IPv6 capability by their end users.

> - Increased price of Legacy IP space on the secondary market (changing the formula) -- strictly speaking, this presentation was still in "primary market" era for LACNIC/ARIN/AFRINIC

While that’s true, even at current prices, IPv4 addresses are cheaper to buy and/or lease than CGN.

> IPv6 migration is not generally aided by CGNAT, but CGNAT deployment is generally aided by IPv6 deployment; to reiterate the earlier point, any ISPs deploying CGNAT without first deploying IPv6 are burning cash.

Yep.

I still think that implementing CGN is a good way to burn cash vs. the alternatives, but YMMV.

Owen

> 
> - Jima
> 
> From: NANOG On Behalf Of Owen DeLong
> Sent: Sunday, February 21, 2021 16:59
> To: Steve Saner
> Cc: nanog at nanog.org
> Subject: Re: CGNAT
> 
> 
> On Feb 18, 2021, at 8:38 AM, Steve Saner wrote:
> 
>> We are starting to look at CGNAT solutions. The primary motivation at the moment is to extend current IPv4 resources, but IPv6 migration is also a factor.
> 
> IPv6 Migration is generally not aided by CGNAT.
> 
> In general, the economics today still work out to make purchasing or leasing addresses more favorable than CGNAT.
> 
> It’s a bit dated by now, but still very relevant, see Lee Howard’s excellent research presented at the 2012 Rocky
> mountain v6 task force meeting:
> 
> https://www.rmv6tf.org/wp-content/uploads/2012/11/TCO-of-CGN1.pdf
> 
> Owen
> 
> 
> We've been in touch with A10. Just wondering if there are some alternative vendors that anyone would recommend. We'd probably be looking at a solution to support 5k to 15k customers and bandwidth up to around 30-40 gig as a starting point. A solution that is as transparent to user experience as possible is a priority.
> 
> Thanks
> 
> -- 
> Steve Saner
> ideatek HUMAN AT OUR VERY FIBER
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