Chapter 5

1. The command to apply a type to a TCP port is created with semanage. For instance, to apply the ssh_port_t type to TCP port 10122, execute the following command:

   # semanage port -a -t ssh_port_t -p tcp 10122

   However, this only works as long as the port itself is not already explicitly mapped to an SELinux type. You can query whether this is the case with sepolicy, for example:

   # sepolicy network -p 10122

   If the port is part of an unreserved range, then it can be altered.

2. No, SECMARK is local to the system. Once a network packet is received by the Linux host, the SECMARK rules will associate a label with that network packet, but this label is only retained in memory on the system itself. Once a packet leaves the Linux system, it will not show any trace of SECMARK labeling.
3. The subcommands used by semanage are ibendport (to apply a label or sensitivity to an InfiniBand network port) and ibpkey (to apply a label or sensitivity to a partition key).
4. While labeled IPsec...