Useful Exim Commands with Examples
Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix/Linux systems connected to the Internet. It is freely...
Category : Trainings
Solaris OK prompt commands
What is OK Prompt? Most of the time, when you start the server with Solaris OS installed, it boots at run level 2 or run...
The difference between fork(), vfork(), exec() and clone()
Fork: The fork call basically makes a duplicate of the current process, identical in almost every way (not everything is copied over, for example, resource...
ELK Stack – Upgrade from 2.x to 5.x
Elasticsearch Snapshot and Restore https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-snapshots.html Elasticsearch Migration Helper Plugin cd /usr/share/elasticsearch/ ./bin/plugin install https://github.com/elastic/elasticsearch-migration/releases/download/v2.0.4/elasticsearch-migration-2.0.4.zip you may get updated command from here -> Elasticsearch Migration Plugin...
Asterisk Server Security – SIP security
If your SIP server is exposed to internet. Then you need to take some measure even if you have fail2ban installed. Fail2Ban keep track of...
netstat – Find number of active connections in Linux using netstat
The “netstat” command is quite useful for checking connections to your machine. If we wanted to see ALL of the connections (which i really recommend...
DNS firewall – Its time to try DNS firewall
[vsw id=”1xWSU4DCNZ4″ source=”youtube” width=”425″ height=”344″ autoplay=”no”] https://www.isc.org/wp-content/uploads/2017/12/RPZ-webinar7.ppt.pdf https://www.isc.org/mission/webinars/ http://www.securityzones.net/images/downloads/Rackspace-RPZ-Case-Study.pdf https://kb.isc.org/article/AA-00525/110/%20Building-DNS-Firewalls-with-Response-Policy-Zones-RPZ.html http://www.securityzones.net/images/downloads/BIND_RPZ_Installation_Guide.pdf ...