Is IPv6 Less Secure Without NAT?
NAT (Network Address Translation) is an IPv4 tool that is not used in most IPv6 deployments. This has caused some users to ask whether IPv6 is as secure as IPv4. What is NAT? NAT is a tool that allows multiple computers behind an Internet connection to share the single address of that connection. Thus, if […]
How do tshark, ngrep, and tcpdump Differ and When to Use Them
What happens on a network has always been an interest of mine. In graduate school in the 1980s, I worked on networking software. Later I used software protocol analyzers such as netwatch (later the commercial LANWatch) to dissect packets. A few years ago I contributed to what is now the Wireshark protocol analyzer. Lanwatch uses […]
Three Measures of Availability in Cybersecurity
In Learning Tree Course 468, Introduction to Cybersecurity, we talk about three core elements of cybersecurity: confidentiality, integrity, and availability. The latter probably gets the least attention. It gets limited attention in Course 450, Introduction to Networking, too. Since availability is an essential pillar of cybersecurity, we’ll look at three important availability metrics here: Uptime […]
Mozilla To End ftp Support. What Are the Alternatives?
In March of this year, Mozilla followed in the steps of Google and announced the upcoming end to support for the ftp protocol in its browser. That is a very good thing! The ftp URI is the mechanism for browsers to use FTP (the File Transfer Protocol) to send and receive data from servers supporting […]
Dovecot is Now My Favorite Unix/Linux IMAP Mail Download Server
As you may know, there are two kinds of email systems: Outlook, and everything else. The non-Outlook-based email world consists mainly of three kinds of software: MDAs, MUAs, and anti-spam/antivirus. Dovecot is the glue between your MDA and your MUA.[gview file=”https://blog.learningtree.com/wp-content/uploads/pdf/dovecot-email-flow.pdf”] MDAs are the mail delivery agents, such as SendMail, PostFix, OpenSMTPD, and more. An […]