Chapter 24. DHCP
The
dhcpd daemon is used in Red Hat Enterprise Linux to dynamically deliver and configure Layer 3 TCP/IP details for clients.
The dhcp package provides the DHCP server and the
dhcpd daemon. Enter the following command to see if the dhcp package is installed:
~]# rpm -q dhcp
package dhcp is not installed
If it is not installed, use the
yum utility as root to install it:
~]# yum install dhcp24.1. DHCP and SELinux
When
dhcpd is enabled, it runs confined by default. Confined processes run in their own domains, and are separated from other confined processes. If a confined process is compromised by an attacker, depending on SELinux policy configuration, an attacker's access to resources and the possible damage they can do is limited. The following example demonstrates dhcpd and related processes running in their own domain. This example assumes the dhcp package is installed and that the dhcpd service has been started:
- Run the
getenforcecommand to confirm SELinux is running in enforcing mode:~]$
getenforceEnforcingThe command returnsEnforcingwhen SELinux is running in enforcing mode. - Enter the following command as the root user to start
dhcpd:~]#
systemctl start dhcpd.serviceConfirm that the service is running. The output should include the information below (only the time stamp will differ):~]#
systemctl status dhcpd.servicedhcpd.service - DHCPv4 Server Daemon Loaded: loaded (/usr/lib/systemd/system/dhcpd.service; disabled) Active: active (running) since Mon 2013-08-05 11:49:07 CEST; 3h 20min ago - Run following command to view the
dhcpdprocesses:~]$
ps -eZ | grep dhcpdsystem_u:system_r:dhcpd_t:s0 5483 ? 00:00:00 dhcpdThe SELinux context associated with the dhcpd process issystem_u:system_r:dhcpd_t:s0.
