Computing

Computers and information management topics

Two common Linux based firewall systems that I have used are IPCop and IPFire. IPCop appears to be no longer a going project. IPFire appears to be based on either IPCop or it is a fork of IPCop but I'm not sure. IPFire is a going project with regular updates, new add-ons and growth. Both have local domain name systems (DNS) used to gather domain information and cache it locally for the benefit of the system inside, or on the green network, of the firewall. Each uses a different solution but with each there is a need from time-to-time where you'd like to flush the local DNS cache. Procedures to do so are shown below.

To test an IMAP server using Telnet (expected server responses in italics):

telnet imap.example.com 143
* OK imap.example.com IMAP4rev1 v12.202 server ready
0 login username password
0 OK [capabilities list] logged in
0 logout
* BYE logging out

If you receive the expected responses you have confirmed the IMAP server is functioning and accepting your account authentication.

With a few custom configuration settings, and creative use, ssh can make it very easy to manage multiple computers.

Keys can eliminate the need to enter passwords every time you connect between two specific computers.