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 available under the terms of the GNU General Public Licence. Exim is used for locating the spam activity on the servers. There is a great …
Read More »Top 25+ Windows System Administration Interview Questions
Top 25+ MCSE Interview Questions for System Admins
A collection of 25+ top MCSE interview questions with answers for System Admins. MCSE (Microsoft Certified Solutions Expert) is a senior level certification from Microsoft. MCSA (Microsoft Certified Solutions Associate) is an entry level certification. If a candidate has MCSE certification, then he is allowed to go to expert level. …
Read More »Solaris OK prompt commands
Last updated on November 2nd, 2019 at 11:11 pmWhat is OK Prompt? Most of the time, when you start the server with Solaris OS installed, it boots at run level 2 or run level 3, which are multi-user states with access to full system and network resources. Occasionally, you might …
Read More »The difference between fork(), vfork(), exec() and clone()
Last updated on November 5th, 2019 at 06:45 amFork: The fork call basically makes a duplicate of the current process, identical in almost every way (not everything is copied over, for example, resource limits in some implementations but the idea is to create as close a copy as possible). The …
Read More »ELK Stack – Upgrade from 2.x to 5.x
Last updated on June 14th, 2018 at 12:25 pmElasticsearch 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 Install You may download plugin from here -> Elasticsearch Migration Plugin After plugin install, access plugin using …
Read More »App Store Optimization Checklist – ASO Tips
Last updated on February 27th, 2018 at 06:16 pmApp Store Optimization is a way of ensuring your app meets app store ranking criteria and rises to the top of a search results page. But how does a marketer optimize for better discover-ability in an app store? To help you boost …
Read More »Asterisk Server Security – SIP security
Last updated on February 27th, 2018 at 06:16 pmIf your SIP server is exposed to internet. Then you need to take some measure even if you have fail2ban installed. Fail2Ban keep track of the logs while blocking the attacks and some of the attacks might occur while fail2ban start jump …
Read More »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 you don’t do unless you’re trying to debug something and then you should probably pipe it to a file) we could use the “netstat -a” …
Read More »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 Webinars and other Presentations given by ISC 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
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