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It’s a good future-proofing investment by AWS. IPv4 is not going away anytime soon. We’ll be dependent on IPv4 for a long time. IPv4 scarcity only hits in cert

It’s a good future-proofing investment by AWS. IPv4 is not going away anytime soon. We’ll be dependent on IPv4 for a long time. IPv4 scarcity only hits in certain segments. It doesn’t hit the major players. The real problem is the hoarding by the major players. AWS will most likely never use that many IP addresses. I know that sounds like a stretch based on what we’re led to believe about running out of IPv4 addresses. I don’t know their IPv4 utilization, so it’s a guess. My guess is based on how we deploy internet facing services these days. It’s less dependent on needing lots of public IPs.

labawi 6y ago
IMO it's good for the internet if few entities were to hoard most IPv4 addresses. Only while IPv4's are sufficiently available will we keep using IPv4-only networks and keep prolonging our miseries. My ISP only gives CGNAT or is happy to rent IPv4 for a premium, one address at a time. Keeping IPv6 out helps the IPv4 margins and staves off competition.
shiftpgdn 6y ago
According to the article AWS usage is at 47% of their IP pool.
kaliszad 6y ago
You cannot use IPv4 100% efficiently. Even if you approach 90% usage, that would probably be very optimistic. AWS has probably millions of physical servers by now (they had ca. 1,4 million servers by December 2014 it seems) each with probably hundreds of services each needing an IP. Yes, you can stretch 10.0.0.0/8 with NATs all over the place but at some point, you need the public IP. With that kind of appetite you need multiple /8s of IPv4 space just to keep things running. I don't think they are crazy buying that much address space and concurrently improving IPv6 support - they most likely really need it.
- tudelo 6y ago
  > You cannot use IPv4 100% efficiently. Can you expand on this a bit? I'm not a networking guru but it's my understanding that an IP address is an IP address, how could it be used more or less efficient?
  - ArchOversight 6y ago
    Each time you subnet you lose three or more IP's. A /24 has: - .0 - network address - can't be used - .255 - broadcast On top of that you generally need at least 1 more IP address that is the gateway for that network. - .1 - Usually If you have a network with fail-over gateways generally you need to assign them individual IP's, so you end up with: - .1 - floating IP - .2 - router 1 - .3 - router 2 If you end up subnetting down into small subnets to give customers only let's say 16 IP's, (so a /28 (32 bits - 4 bits)) customers can only use 13 of those addresses (network/broadcast/gateway are already taken). This gets worse as you go smaller, because each time you subnet you end up losing more IP's to the network/broadcast/gateway.
    - AmericanChopper 6y ago
      I’ve been assigned a .0 public IPv4 address by AWS before. I was a bit confused when I first saw it, but it worked just fine.
      - ArchOversight 6y ago
        Sure, there is no problem with using a .0. For example in 10.0.0.0/23 you'd have 10.0.1.0/32 As a perfectly valid IP address. Also, routing an entire block allows you to use all of the IP's in said block. So there are ways to do it efficiently, but with routing a block that block is not considered on-network and thus doesn't have a broadcast address nor can it use one.
      - gene91 6y ago
        That works when the subnet is /23 or larger.
      - adamcharnock 6y ago
        I had this too. I assumed it would be fine - and it mostly was. However, we tracked a weird bug with some of the companies IoT products not being able to open a connection to the .0. Never figured out if this was a dodgy IP stack on the devices, or if it was the particular mobile carrier in that area of the world. My money would be on the latter though.
- outworlder 6y ago
  > AWS has probably millions of physical servers by now (they had ca. 1,4 million servers by December 2014 it seems) each with probably hundreds of services each needing an IP. Why would any significant fraction of these servers require public IPs? And services for that matter. I wouldn't be surprised if most of them are in private VPCs with only very few endpoints exposed. If you are referring specifically to AWS, having servers in public subnets is actually an anti-pattern. You may want to do so with bastion hosts and a handful of more specialized services. For everything else, put them behind a load balancer. A single NLB will take one IP per availability zone and will be able to service hundreds of servers, if not more. Then you have things like Cloudfront and the like. Not many IPs are needed, overall, compared to the number of actual servers.
oblio 6y ago
> AWS will most likely never use that many IP addresses. Are you sure about that? A comment here said that they had 1.4 million servers in 2014, and AWS at the time was probably 1/50th of what it is now. On top of that, I think they have some IoT offerings, and who knows what they're going to offer in the future? They're basically building an internet-sized platform to run half the internet on top of it.
- goatinaboat 6y ago
  Every tenant in AWS has an independent address space - there could be a million 10.0.0.0/8’s inside and no one would be any the wiser.

labawi 6y ago

IMO it's good for the internet if few entities were to hoard most IPv4 addresses. Only while IPv4's are sufficiently available will we keep using IPv4-only networks and keep prolonging our miseries. My ISP only gives CGNAT or is happy to rent IPv4 for a premium, one address at a time. Keeping IPv6 out helps the IPv4 margins and staves off competition.

shiftpgdn 6y ago

According to the article AWS usage is at 47% of their IP pool.

kaliszad 6y ago

You cannot use IPv4 100% efficiently. Even if you approach 90% usage, that would probably be very optimistic. AWS has probably millions of physical servers by now (they had ca. 1,4 million servers by December 2014 it seems) each with probably hundreds of services each needing an IP. Yes, you can stretch 10.0.0.0/8 with NATs all over the place but at some point, you need the public IP. With that kind of appetite you need multiple /8s of IPv4 space just to keep things running. I don't think they are crazy buying that much address space and concurrently improving IPv6 support - they most likely really need it.

tudelo 6y ago
> You cannot use IPv4 100% efficiently. Can you expand on this a bit? I'm not a networking guru but it's my understanding that an IP address is an IP address, how could it be used more or less efficient?
- ArchOversight 6y ago
  Each time you subnet you lose three or more IP's. A /24 has: - .0 - network address - can't be used - .255 - broadcast On top of that you generally need at least 1 more IP address that is the gateway for that network. - .1 - Usually If you have a network with fail-over gateways generally you need to assign them individual IP's, so you end up with: - .1 - floating IP - .2 - router 1 - .3 - router 2 If you end up subnetting down into small subnets to give customers only let's say 16 IP's, (so a /28 (32 bits - 4 bits)) customers can only use 13 of those addresses (network/broadcast/gateway are already taken). This gets worse as you go smaller, because each time you subnet you end up losing more IP's to the network/broadcast/gateway.
  - AmericanChopper 6y ago
    I’ve been assigned a .0 public IPv4 address by AWS before. I was a bit confused when I first saw it, but it worked just fine.
    - ArchOversight 6y ago
      Sure, there is no problem with using a .0. For example in 10.0.0.0/23 you'd have 10.0.1.0/32 As a perfectly valid IP address. Also, routing an entire block allows you to use all of the IP's in said block. So there are ways to do it efficiently, but with routing a block that block is not considered on-network and thus doesn't have a broadcast address nor can it use one.
    - gene91 6y ago
      That works when the subnet is /23 or larger.
    - adamcharnock 6y ago
      I had this too. I assumed it would be fine - and it mostly was. However, we tracked a weird bug with some of the companies IoT products not being able to open a connection to the .0. Never figured out if this was a dodgy IP stack on the devices, or if it was the particular mobile carrier in that area of the world. My money would be on the latter though.
outworlder 6y ago
> AWS has probably millions of physical servers by now (they had ca. 1,4 million servers by December 2014 it seems) each with probably hundreds of services each needing an IP. Why would any significant fraction of these servers require public IPs? And services for that matter. I wouldn't be surprised if most of them are in private VPCs with only very few endpoints exposed. If you are referring specifically to AWS, having servers in public subnets is actually an anti-pattern. You may want to do so with bastion hosts and a handful of more specialized services. For everything else, put them behind a load balancer. A single NLB will take one IP per availability zone and will be able to service hundreds of servers, if not more. Then you have things like Cloudfront and the like. Not many IPs are needed, overall, compared to the number of actual servers.

oblio 6y ago

> AWS will most likely never use that many IP addresses. Are you sure about that? A comment here said that they had 1.4 million servers in 2014, and AWS at the time was probably 1/50th of what it is now. On top of that, I think they have some IoT offerings, and who knows what they're going to offer in the future? They're basically building an internet-sized platform to run half the internet on top of it.

goatinaboat 6y ago
Every tenant in AWS has an independent address space - there could be a million 10.0.0.0/8’s inside and no one would be any the wiser.