advanced·20 min·Paid
Replies Leave the Server, But Never Reach the Client
A permitted inside service answers, but its return traffic disappears at the firewall.
Scenario
Dovetail Museum's outside client can start a permitted session with an inside service, but responses disappear on the way back. Unsolicited connections from the outside must remain blocked. Use the traffic direction and connection state to restore replies without opening a broad path.
Learning objectives
- acl
- nftables
- stateful firewall
- connection tracking
Topology and configuration
This environment contains 3 devices (2 Hosts, 1 Router). You configure and troubleshoot the networking skills listed above.