How can I troubleshoot network or connectivity issues that prevent my application from reaching the Amazon Bedrock endpoint?

To troubleshoot network or connectivity issues preventing your application from reaching the Amazon Bedrock endpoint, start by verifying your network configuration and AWS service permissions. First, check if your application’s environment (e.g., EC2 instance, Lambda function, or on-premises server) has proper outbound internet access or a configured VPC endpoint for Bedrock. For example, if your application runs in a private subnet, ensure it has a NAT gateway, VPC endpoint, or direct internet access via a public subnet. Security groups and network ACLs must allow outbound HTTPS traffic (port 443) to Bedrock’s endpoints. Additionally, confirm that your AWS Identity and Access Management (IAM) roles or users have the bedrock:InvokeModel permission and that Bedrock is enabled in your AWS account (it’s disabled by default). A common oversight is forgetting to enable Bedrock via the AWS Management Console or CLI before making API calls.

Next, test connectivity to the Bedrock endpoint directly. Use tools like curl, telnet, or nslookup to verify DNS resolution and reachability. For instance, running nslookup bedrock.us-east-1.amazonaws.com checks if your DNS resolves the endpoint correctly. If DNS resolution fails, your network might block AWS endpoints, or you might need to configure a DNS resolver. If the endpoint is reachable but returns errors, inspect HTTP status codes and error messages. For example, a 403 Forbidden error suggests IAM permission issues, while a timeout indicates network blocking. Temporarily disable firewalls, proxies, or content filters to rule them out as blockers. If your application runs in a corporate environment, ensure AWS endpoints aren’t restricted by organizational policies. You can also test using the AWS CLI: aws bedrock list-foundation-models --region us-east-1 validates both permissions and connectivity.

Finally, monitor traffic and logs to isolate the issue. Enable VPC Flow Logs to track outbound requests to Bedrock’s IP ranges, which you can find in AWS’s published IP address ranges. Look for REJECTED entries indicating network-level blocking. Check CloudTrail logs for Bedrock API activity—if requests aren’t logged, the issue likely occurs before reaching AWS (e.g., network misconfiguration). For applications using AWS SDKs, enable debug logging to capture retries, timeouts, or SSL handshake failures. For example, setting the AWS_DEBUG environment variable in Python’s Boto3 can reveal SSL certificate mismatches or proxy configuration errors. If the problem persists, test from a different environment (e.g., a temporary EC2 instance with open security groups) to determine if the issue is environment-specific. If all else fails, review AWS Service Health Dashboard for regional Bedrock outages and contact AWS Support with relevant logs and error details.