Cloud NAT vs Home Router Explained | Generated by AI
Question: The NAT router in the diagram uses a 172.x.x.x address, which looks like a cloud provider address (AWS/GCP). If it were a home router, shouldn’t it be 192.168.0.1? Can a home computer connect to a NAT gateway in the cloud?
Answer:
Clarifying the 172.x.x.x Address
First, important distinction:
| Range | Type | Used by |
|---|---|---|
172.16.0.0 – 172.31.255.255 |
Private (RFC 1918) | Internal networks |
172.32.0.0 – 172.255.255.255 |
Public | Anyone assigned by IANA |
172.38.1.5 is NOT in the private range (172.16–172.31), so it is a legitimate public IP address — not a cloud-internal address. It simply belongs to whoever was assigned that block by IANA.
So in the diagram, the NAT router is just a regular border router with a public IP, not necessarily a cloud NAT gateway.
Typical Home Router Setup
You are correct that a typical home router uses:
Internet (Public IP, e.g. 203.x.x.x)
│
[Home Router] ← WAN side: public IP assigned by ISP
│ ← LAN side: 192.168.0.1 (gateway for home devices)
Home Devices
192.168.0.x
The home router itself performs NAT — it translates all internal 192.168.x.x devices to one single public IP assigned by the ISP.
Can a Home Computer Connect to a Cloud NAT Gateway?
Yes, absolutely. There are several real-world scenarios:
Scenario 1: VPN to Cloud (Most Common)
Home PC (192.168.0.x)
│
Home Router (NAT #1) → Public IP
│
Internet
│
VPN Tunnel (encrypted)
│
Cloud VPN Gateway (e.g. AWS VPN Gateway)
│
Cloud Private Network (172.31.x.x on AWS)
│
Cloud NAT Gateway
│
Cloud resources / Internet egress
Home PC traffic gets double-NATted: once at home router, once at cloud NAT.
Scenario 2: AWS/GCP NAT Gateway for Outbound Traffic
Cloud providers use NAT gateways so that private cloud VMs (with no public IP) can still reach the Internet:
Cloud VM (10.0.x.x or 172.31.x.x) ← private, no public IP
│
AWS NAT Gateway (has public Elastic IP)
│
Internet
This is the same concept as the diagram — just hosted in cloud infrastructure.
Scenario 3: Direct Connect / Leased Line
Enterprises can connect office networks directly to cloud private networks via AWS Direct Connect or Google Cloud Interconnect, bypassing the public Internet entirely.
Key Takeaway
| Scenario | NAT Location | Who does NAT |
|---|---|---|
| Home network | Home router | Router with ISP-assigned public IP |
| Cloud VM → Internet | Cloud NAT Gateway | AWS/GCP managed service |
| Home → Cloud (VPN) | Both home router AND cloud gateway | Double NAT |
The concept of NAT is identical regardless of whether it runs on a home router, a corporate border router, or a cloud-managed gateway. The diagram simply illustrates the universal principle — the 172.38.1.5 just happens to be the public IP assigned to that NAT router.