System configuration and management
Network services
Network services are an important subset of the exam objectives. RHCE candidates should be capable of meeting the following objectives for each of the network services listed below:
HTTP/HTTPS
DNS
NFS
SMB
SMTP
SSH
NTP
Database services
DNS servers comes in several types such as master, slave, forwarding and cache, to name a few examples, with cache-only DNS being the one that is easier to setup. The cache-only DNS server is also known as resolver, which will query DNS records and fetch all the DNS details from other servers, and keep each query request in its cache for later use so that when we perform the same request in the future, it will serve from its cache, thus reducing the response time even more.
https://www.tecmint.com/install-configure-cache-only-dns-server-in-rhel-centos-7/
HTTP/HTTPS
https://www.certdepot.net/rhel7-configure-apache-virtual-host/
https://www.linux.com/blog/multiple-virtual-hosts-centos-7-or-rhel-7
https://www.certdepot.net/rhel7-deploy-apache-basic-cgi-application/
https://www.certdepot.net/rhel7-configure-apache-private-directories/
https://www.certdepot.net/rhel7-configure-apache-group-managed-content/
https://www.certdepot.net/rhel7-configure-apache-tls-security/
NFS
https://www.certdepot.net/rhel7-provide-nfs-network-shares-specific-clients/
https://www.certdepot.net/rhel7-provide-nfs-network-shares-suitable-group-collaboration/
https://www.certdepot.net/rhel7-use-kerberos-control-access-nfs-network-shares/
SMB
https://www.certdepot.net/rhel7-provide-smb-network-shares/
https://www.certdepot.net/smb-provide-network-shares-suitable-group-collaboration/
SMTP
https://www.certdepot.net/rhel7-configure-system-forward-email-central-mail-server/
SSH
https://www.certdepot.net/rhel7-configure-ssh-key-based-authentication/
https://www.certdepot.net/rhel7-configure-additional-ssh-options/
NTP
https://www.certdepot.net/ntp-synchronize-time/
https://servicesblog.redhat.com/2018/11/13/tips-for-passing-red-hat-certification-exams/
https://www.redhat.com/en/services/training/ex300-red-hat-certified-engineer-rhce-exam