0

The VPC documentation says:

When you create a VPC, we recommend that you specify a CIDR block (of /16 or smaller) from the private IPv4 address ranges as specified in RFC 1918:

  • 10.0.0.0 - 10.255.255.255 (10/8 prefix)
  • 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
  • 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

You can create a VPC with a publicly routable CIDR block that falls outside of the private IPv4 address ranges specified in RFC 1918; however, for the purposes of this documentation, we refer to private IP addresses as the IPv4 addresses that are within the CIDR range of your VPC.

What happens if a VPC is created with a range outside of those ranges, for example, 172.40.0.0/16? Probably nothing immediately, but what would I need to watch out for if I did that?

1

With a typical configuration for your router, this would mean that all packets destined for a "real" internet IP address like 172.40.1.2 (say) would not be reachable from your network since your router would try to find the relevant Internet device within your network.

1

Let us assume you have assigned an IP address to a host eg:172.40.0.1 It is a public IP address which means someone already bought this IP. Let us see the whois data.

IP address: 172.40.0.1
hostname:   172.40.0.1
ISP:    T-Mobile USA
Country:    United States (US) flag
latitude:   37.751
longitude:  -97.822

Now if you are using custom DNS server for VPC then you can make use of it inside VPC locally. Although we may configure it locally, networks still create conflicts because we don't have control on few of the system discovery methods.

0

Your networking will be just broken, I mean your container will be not acessible from outside (internet) nor your PVC could send anything to outside to the world. Amazon had preconfigured their listed private networks to be only accepted as a source and destination address pools for PVC. Having two own PVC on same real hardware node it is possible they could communicate just to each other, having both addresses assigned from unauthorized by amazon pool 172.40.1.2 and, say, 172.40.1.1, but I'm not sure, it depends on networking setup amazon have there.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.