Overview System administrators frequently need TLS certificates for systems that are not publicly accessible (and can leverage OpenSSL CA.pl as a solution), including: A public certificate authority may not be appropriate for these systems, especially when their hostnames are only resolvable … [Read more...] about How to Create a Private CA with OpenSSL CA.pl
Apache Access Log IP Address
This article will document how to sort the apache access log IP address list. You may be analyzing the ip addresses in a given apache access log for any number of reasons, including DDOS attacks. We will document a single command to extract the unique IP addresses, count them, and sort them by most … [Read more...] about Apache Access Log IP Address
Redhat security patch backport
This article will detail how Redhat manages security patches in backports. This article will focus on the Apache httpd package but may be relevant to other packages as well. You may notice or be alerted that a specific package version contains vulnerabilities and that the Redhat package manager (yum … [Read more...] about Redhat security patch backport
Firewall Redhat
This article will demonstrate how to manage a firewall on a Redhat server. Firewall functions that will be covered include how to check the firewall status, start, stop, enable, and disable it. The examples below were performed on RHEL 8.x. The default firewall on RHEL 8 is firewalld and is … [Read more...] about Firewall Redhat
Linux socket data on servers
This article will demonstrate how to show Linux socket data on servers, both Redhat and Ubuntu. One primary use case for obtaining this kind of data is when a Linux subscription or support console wants to properly license your organization based on number of sockets. The script below is scalable to … [Read more...] about Linux socket data on servers
How to mount NFS share on Linux
This article will demonstrate how to mount an NFS share on Linux. The instructions will work for both Redhat and Ubuntu Operating Systems. First, let's define NFS. NFS stands for Network File System, which is a distributed file system protocol that allows you to share a directory over the … [Read more...] about How to mount NFS share on Linux
How to disable weak HMAC Algorithms
This article will demonstrate how to disable weak HMAC algorithms in your Linux OS. This article will assume Ubuntu as the underlying Linux Operating System, but the general principal can be applied to Redhat as well. For demonstration purposes, let us assume a vulnerability scan has informed you … [Read more...] about How to disable weak HMAC Algorithms
No matching host key type found – SSH and SFTP
The purpose of this article is to demonstrate how to use ssh to remotely connect to an older linux host from a newer version of openssh when receiving the no matching host key type found error. The example in this article was used against an older RHEL 6.5 server. Additionally, the article will … [Read more...] about No matching host key type found – SSH and SFTP