Restricting network access

It is possible to restrict network access using application-specific configurations, generalized userspace restrictions (e.g., TCP wrappers), host (kernel) level firewalls, and network firewalls.

For a specific application or protocol, implement rules to restrict access at the application, host, and network levels. Verify that your rules are working properly, i.e., that the protocol is being blocked where you think it is being blocked.

Once you've implemented a complete block, implement a partial block (e.g., allow some hosts and restrict other hosts).

Note that while you can do this exercise in a virtual environment, it is probably easier to do it on a regular network you control (e.g., a home network).