Blog · Domain
Networking
5 articles, each explaining one topic from the documentation and ending at a stage you can play.
SAA-C03 · Networking
How a private subnet reaches the internet: the NAT gateway, hop by hop
A NAT gateway lets private instances start connections out while nothing on the internet starts one in. Follow every hop, and see the address the far end sees.
Ends at Private but Connected Free at release6 min read · video coming
SAA-C03 · Networking
Security group or network ACL: which one dropped the packet?
Security groups are stateful and only allow. Network ACLs are stateless, numbered and can deny. Follow one HTTPS request to see which layer drops what.
Ends at Guard Rails Paid5 min read · video coming
SAP-C02 · Networking
Transit gateway route tables: association and propagation, with one packet
Association picks the table a packet is looked up in. Propagation picks which tables know a VPC. Follow one packet to see how a transit gateway segments.
Ends at Routing Domains Paid5 min read · video coming
SAA-C03 · Networking
What actually makes a subnet public
Not its name, not a public IP, not the gateway alone. The subnet's route table decides, and the main route table decides for every subnet you forgot.
Ends at Open for BusinessFree5 min read · video coming
SAA-C03 · Networking
Why can't my private subnet reach S3? Gateway and interface endpoints
With no internet gateway or NAT, a private subnet can still reach AWS services. A gateway endpoint adds a route; an interface endpoint adds an address.
Ends at Shortcut to S3 Paid5 min read · video coming