Another aide-memoir, these are the setting required to enable a sipgate account (and PSTN number) to connect to a phone registered to your Elastix / Asterisk PBX:
Read more…
Two videos which explain about VRF configuration and troubleshooting. the first is an excellent overview and the second a practical demonstration of VRF configuration:
This video (1 hour 52 minutes in length) is an excellent tutorial / introduction / refresher on the subject of MPLS and MPLS VPN.
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Attacks on Asterisk-based telephony systems are not uncommon. This video explains how to mitigate some attack vectors:
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Another Aide memoir:
UNIX SECURITY TECHNICAL IMPLEMENTATION GUIDE
Version 5, Release 1
Can be downloaded from: http://iase.disa.mil/stigs/downloads/pdf/unix-stig-v5r1.pdf
At its core an X.509 certificate is a digital document that has been encoded and/or digitally signed according to RFC 5280.
In fact, the term X.509 certificate usually refers to the IETF’s PKIX Certificate and CRL Profile of the X.509 v3 certificate standard, as specified in RFC 5280, commonly referred to as PKIX for Public Key Infrastructure (X.509). (See this post for an explanation of the SSL/TLS Handshake and Record Protocols). Read more…
DNS servers can be attacked using various techniques including:
One of the simplest ways to defend is to strictly limit zone transfers between nameservers by defining an ACL. Many system administrators allows BIND to transfer zones in bulk outside of their network or organisation. This is an attack vector. You can prevent this by using ACLs: Read more…
named.conf
Create /etc/named.conf file specify the directory location of other files used by DNS: Read more…
A Record
The majority of DNS records are “A” records. A records allow for you to point different sections of your domain to different IP addresses or servers. For example, this would be useful for having “www.domain.com” point to your web server’s IP address and “mail.domain.com” point to your mail server’s IP address. Each record includes a “Host Name” value and a corresponding IP Address. Read more…
This is a link to a brief description of what happens in a Linux system, from the time that you turn on the power, to the time that you log in and get a bash prompt. Understanding this will be helpful when you need to solve problems or configure your system.
http://www.tldp.org/HOWTO/From-PowerUp-To-Bash-Prompt-HOWTO.html
Greg O’Keefe, gcokeefe@postoffice.utas.edu.au
