directconnect

SKILL.md

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?

Goal
Reference

Choose dedicated vs hosted vs a link aggregation group, then complete the cross connect
choosing a Direct Connect connection type

Create a private, public, or transit virtual interface and bring up BGP
creating a virtual interface and configuring BGP

Reach many VPCs over one connection through a Direct Connect gateway
connecting many VPCs through a Direct Connect gateway

Encrypt traffic in transit with MACsec or a private IP Site-to-Site VPN
encrypting traffic over Direct Connect

Make the connection survive a failure and tune failover speed
making a Direct Connect connection resilient

Bundle connections into one logical link and manage members
managing link aggregation groups

Connect on-premises sites to each other over the AWS backbone
setting up SiteLink

Move from a virtual private gateway to a transit gateway without dropping traffic
migrating from a virtual private gateway to a transit gateway

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 directconnect API 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 directconnect API 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 grant directconnect:* on resource * or attach
any *FullAccess managed 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.

Additional Resources

AWS Direct Connect User Guide

Security in AWS Direct Connect (AWS Direct Connect User Guide)

AWS Direct Connect product page

AWS Direct Connect pricing