Here are the resources I used to harden the 2 serves at Eircom

port information

Excellent hardening guide

need to upload Braum hardening document

RedHat 8

There are enough differences in RHEL 7 that make the previous documents hard to follow.

Here is a link to the best practices from Redhat

Securing RHEL 7 PDF

Securing RHEL 7 document

4.1 Nosuid Nodev Noexec Removing unneeded FS drivers

4.2 noclobber

4.3 Aide

4.4 SELinux

4.5 Boot security

4.6 Execshield

4.7 Prelink Applies only to RHEL 5

5 Disabling Standard Services

6.1 Setting Default umask Disable Special Services

6.3 Configuring the MTA

7 Network Configuration

8 Wireless Networking

9 IPv6

10 TCP-wrappers

11 IPTables

12 Uncommon network protocols

13 Logging and Auditing

14 Implementing Logrotate

15 Ssh configuration

16 PAM configuration

17 Enable SHA-512 hashing for all password encryption

18 Restrict root login access to the system console

19 Require a wheel group for root access

20 User accounts and Environments

21 Hardening standards for the Apache web server