Transit Gateway
3 posts tagged Transit Gateway.
Security group referencing across a Transit Gateway needs two flags, not one
It has to be enabled on the transit gateway and on every VPC attachment. Enable it in one place and it does nothing, with no error. The limitation list is also longer than most people check.
Networking4 minAppliance mode has a prerequisite that silently undoes it
Enable appliance mode and forget route propagation on the associated Transit Gateway route table, and every flow falls back to hash-based Availability Zone selection. The attachment still reports appliance mode enabled.
Networking4 minOne Transit Gateway rule explains both an outage and a security hole
Route lookup happens against the route table associated with the attachment traffic arrived on. That single sentence produces a connection that should work and does not, and a connection that should be impossible and is not.
Networking4 min