AWS Elastic IP architecture

Christopher Morrow morrowc.lists at
Thu May 28 17:03:30 UTC 2015

On Thu, May 28, 2015 at 11:59 AM, Michael Helmeste <elf at> wrote:
>> -----Original Message-----
>> From: NANOG [mailto:nanog-bounces at] On Behalf Of Christopher
>> Morrow
>> Subject: Re: AWS Elastic IP architecture
>> [...]
>> i sort of doesn't matter right? it is PROBABLY some form of encapsulation
>> (like gre, ip-in-ip, lisp, mpls, vpls, etc) ...
>> [...]
> I don't know how the public blocks get to the datacenter (e.g. whether they are using MPLS) but after that I think it is pretty straightforward. All of the VMs have only one IPv4 address assigned out of 10/8. This doesn't change when you attach an Elastic IP to them.

right, so they encap somwhere after between 'tubez' and 'vm'. and
likely have a simple 'swap the ip header' function somewhere before
the vm as well.

> All that is happening is that they have some NAT device somewhere (maybe even just a redundant pair of VMs?) that has a block of public IPs assigned to it and they

i'd question scalability of that sort of thing... but sure, sounds
like a reasonable model to think about.

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