Technology Insights

Asterisk Check T1 Status Because Faxes Sent Via Hylafax Fail

If you have a Asterisk system being used for sending and receiving faxes and all of the sudden the faxes all start failing with various error messages the first thing that should be checked is the status of either the analog telephone lines, the T1’s, or the SIP provider you are using as a outbound proxy. Below I describe some of the error messages that may be received via Hylafax in this example as well as how to check the status of the T1’s themselves to make sure that there are no alarms present before you have to get into troubleshooting Hylafax in detail.

Technology Insights

dpkg: error processing likewise-open (–configure), Join Linux Server To Windows Domain Controller

In the past I have used likewise-open to join Linux servers to a Windows domain controller. There were always at least some issues using likewise-open and even though it was always possible to get it working it was always a pain. Today I started the process and of course ran into an error which is noted below in more detail so I did some research and came across centrify which ended up being much easier and worked without issue. Use the instructions below to install, configure, and use centrify to join a Linux server to a Windows DC.

Technology Insights

iPhone Visual Voicemail Not Working With iOS Beta 6

I updated my iPhone to iOS Beta 6 a couple weeks back and ever since I have not been receiving visual voicemail notifications. Initially I thought people were just not leaving me voicemails but once I finally called into voicemail by holding the number one on my iPhone keypad to check voicemail I realized I had 25 voicemails. Once they were all cleared out I moved on the trying to fix the visual voicemail issue which turns out is really easy to resolve by following the below steps.

Technology Insights

List All IP Addresses Making Port 80 Connections To Linux Server

Earlier while analyzing a Linux server it was pointed out to me that the Apache logs were filling up with constant connections requesting domains that were not configured on the server. To me it looked as if a load balancer somewhere was misconfigured and sending traffic to our IP address by mistake but I needed to open a ticket with the colocation provider to have them look into the issue further since the network in this case is not something I have any control over. Below is a quick Linux command that will output a list of IP addresses making port 80 connections to your server.

Technology Insights

Move Long Running Linux Process To Screen Session

Have a long running Linux process open in a SSH terminal window and need to shutdown your computer without killing it? I run into this on a regular basis and never spent the time looking into a solution but this past weekend I actually decided to look and came up with a cool solution called reptyr. The reptyr application allows you to open screen and migrate the process to the screen terminal and away from the terminal connection opened without screen. This allows you to detach from the window without killing the process. Below is a quick overview of installing reptyr and how to use it.