AWS Direct Connect
Overview
Domain expertise for configuring AWS Direct Connect, the service that gives a customer a private, consistent network link between their own data center or colocation and AWS instead of routing over the public internet. Covers choosing a connection model and completing the cross connect, creating virtual interfaces and bringing up Border Gateway Protocol (BGP), reaching many VPCs through a Direct Connect gateway, encrypting traffic in transit, making the connection resilient, managing link aggregation groups, SiteLink, and migrating from a virtual private gateway to a transit gateway.
This skill is a router. Each customer task maps to a procedure file under references/. Read the
matching reference in full before acting, then follow its constraints and steps. The reference
files are self-contained: each carries its own decision tables, constraints, procedure, and
troubleshooting.
Execute commands using the AWS MCP server when connected (sandboxed execution, audit logging,
observability). Fall back to the AWS CLI otherwise. The Direct Connect console is regional, so pass
the customer's working --region on aws directconnect commands; a Direct Connect gateway is a
global resource but is reached through a regional console view.
Which Direct Connect task do you need?
Routing notes
- Connection model comes first. The choosing-a-connection-type reference is the entry point for a customer with no link yet. It settles dedicated vs hosted vs a link aggregation group, checks location support for the chosen speed, and separates a hosted connection from a hosted virtual interface, a distinction customers confuse constantly. Run it before any cross connect is ordered, since port speed cannot change after the connection is created.
- A connection carries no traffic until a virtual interface exists. After the cross connect is live, the creating-a-virtual-interface reference is the required next step. The virtual interface type (private, public, or transit) decides what the connection can reach and is fixed at creation. The jumbo-frame maximum transmission unit (MTU) should be set at creation but, on a private or transit virtual interface, can be changed later with a brief connectivity disruption.
- One VPC vs many VPCs. A single VPC in one Region can be reached over a private virtual interface to a virtual private gateway. Reaching many VPCs, crossing accounts, or crossing Regions is the Direct Connect gateway reference, which also owns the cross-account transit gateway proposal-and-acceptance handshake.
- Encryption is a separate, deliberate step. Direct Connect is not encrypted in transit by default. The encrypting-traffic reference compares MACsec (Layer 2, over the cross connect) against a private IP Site-to-Site VPN over a transit virtual interface (the recommended IPsec path). Route here whenever the customer mentions regulated data or encryption.
- Resiliency model vs failover speed are two different questions. The resiliency reference covers both: the Resiliency Toolkit sets the topology and service level target, while BGP hold-timer tuning and Bidirectional Forwarding Detection (BFD) set how fast failover actually converges.
- Link aggregation group as a model vs as ongoing management. The connection-type reference introduces the link aggregation group as a model choice at order time. The managing-link-aggregation-groups reference owns ongoing member add/remove and minimum-links behavior, where removing a member can take the whole group down.
- Migration is order-dependent. The virtual-private-gateway-to-transit-gateway migration reference exists because doing the cutover steps out of order drops production traffic. Route any "we outgrew the single-VPC model" request here rather than to the plain Direct Connect gateway reference.
Security Considerations
Direct Connect provides a private link into VPC resources, so the security posture differs from the public internet path. Carry these into every task:
- Not encrypted by default. Direct Connect does not encrypt traffic in transit. You MUST treat encryption as a separate, deliberate step (MACsec or a private IP Site-to-Site VPN) before regulated or sensitive data crosses the link. See the encrypting-traffic reference.
- Physical and colocation security. The link terminates on customer equipment at a Direct Connect location or partner colocation. You SHOULD remind the customer that physical access control and partner trust at that facility are part of the connection's security boundary.
- Monitoring and alerting. You SHOULD recommend CloudWatch alarms on connection state and virtual interface BGP status so connection-state changes and failures trigger alerts rather than relying on manual detection.
- Audit logging. You SHOULD confirm CloudTrail is enabled and logging
directconnectAPI calls (connection, virtual interface, and gateway-association changes) so all configuration changes are captured for audit and compliance. - CloudWatch Logs encryption. You SHOULD encrypt CloudWatch Logs log groups that receive Direct Connect-related logs or alarm state data with a KMS key, so sensitive connection metadata is protected at rest.
- Least-privilege IAM. You MUST scope IAM permissions for
directconnectAPI actions to the specific actions and resources each principal needs, and prefer ephemeral IAM credentials over long-lived IAM user access keys. You MUST NOT grantdirectconnect:*on resource*or attach any*FullAccessmanaged policy; instead scope actions to specific resource ARNs, e.g.arn:aws:directconnect:*:*:dxcon/{connection_id}for a connection, so a compromised principal cannot touch every Direct Connect resource in the account. - Route leaks between VPCs. You SHOULD warn that advertising a supernet that overlaps VPC CIDRs can cause unintended VPC-to-VPC traffic over a shared Direct Connect gateway; mitigate with specific prefixes, separate gateways, or transit gateway blackhole routes.
