Error: a socket operation was attempted to an unreachable network dynamodb

“A socket operation was attempted to an unreachable network” is a client networking failure: the operating system cannot route the connection to the DynamoDB endpoint. On Windows, this is WSAENETUNREACH (10051). Fix the route or endpoint before changing DynamoDB permissions or capacity.

Check the endpoint from the failing environment

1. Read the hostname in the exception. Confirm the configured AWS Region and any endpoint override. Run connectivity checks inside the same machine, container, or workload network as the application.
2. Resolve that hostname and test HTTPS connectivity. A failed ping does not establish that DynamoDB is unavailable; ICMP and HTTPS are different protocols.
3. Check VPN routes, proxy configuration, outbound firewall rules, and whether the resolved IPv4 or IPv6 address has a working route.

# PowerShell; substitute the hostname from your exception.
Resolve-DnsName dynamodb.us-west-2.amazonaws.com
Test-NetConnection dynamodb.us-west-2.amazonaws.com -Port 443

On macOS or Linux, curl -v https://dynamodb.us-west-2.amazonaws.com/ can distinguish DNS, TCP, and TLS failures. An HTTP authentication error from this unsigned request still demonstrates that the endpoint responded; it does not verify an authenticated DynamoDB operation.

For VPC and local connections

• In a private AWS subnet, provide a route through a DynamoDB gateway endpoint, a configured interface endpoint, or a NAT path to the public service. Verify the subnet route table, security-group egress, and network ACLs. Gateway endpoints are regional and do not provide an on-premises path through a VPN.
• With DynamoDB Local, use its HTTP endpoint and published port. Inside a sibling container, localhost points to that container; use the DynamoDB service hostname instead.
• After repairing connectivity, repeat the application request. A subsequent AccessDeniedException is a separate authorization problem.

See Microsoft’s socket error reference, AWS gateway endpoint routing, and local endpoint setup.