Category Linux

2 ways to check DNS SPF Record with Examples

An SPF (Sender Policy Framework) record is a type of TXT record in our DNS zone file. SPF records help identify which mail servers are permitted to send email on behalf of our domain. Adding an SPF record can help…

2 ways to check DNS PTR Record in Linux

DNS PRT record is short for pointer record. It is one of the common Domain Name System (DNS) records. It resolves an IP address to a domain or hostname. It is also called DNS reverse record. The following commands can…

Check SSL TLS cipher suites in Linux

An SSL cipher, or an SSL cipher suite, is a set of algorithms or a set of instructions/steps that helps to establish a secure connection between two entities. SSL cipher suites determine the method through which a secure connection will…

Check SSL Connection with OpenSSL S_client Command

SSL (Secure Sockets Layer) connection is a connection that provides secure communications on the Internet for such things as web browsing, e-mail, instant messaging, and other data transfers. Although SSL was replaced by an updated protocol called TLS (Transport Layer…

Understanding SSL certificates

Server certificates are known as SSL/TLS certificates. It verifies and validates the identity of the certificate holder or applicant before authenticating it. It also establishes an encrypted communication channel and switches the protocol to HTTPS once installed on the server.…