Roskomnazor will inspect the traffic to block prohibited content and make sure traffic between Russian users stays inside the country, and is not re-routed uselessly through servers overseas, where it could be intercepted.
A date for the test has not been set, but is supposed to happen before April 1, according to a law introduced past year.
The official Duma news feed (translated from Russian) said the proposed law on a sovereign Runet (the Russian term for the internet within Russia's borders) would isolate the country from the global network in the event of "targeted large-scale external influence".
The Russian government has been working on the complex cyber defense tactic for several years.
Finanz.ru also reported that local internet services Mail.ru and Yandex.ru were also supportive of the test disconnection.
"Theoretically, the U.S has the ability to cut off Russia's Internet connectivity from outside, but there is no precedent to trace worldwide", said the team leader of Ru-center, one of Russia's largest domain name registrars and hosting providers.
The announcement comes after a draft law called the Digital Economy National Program - which requires Russian internet service providers (ISPs) to make technical changes as the nation prepares for sanctions - was introduced to Russian parliament past year.
The test is being carried out as Russian Federation faces numerous sanctions threats from North Atlantic Treaty Organisation and others over its alleged use of cyber-hacking tactics in global espionage.
But it also is meant to test if all Russian internet traffic can be gathered and routed through a few points controlled by government sources. This is similar to the Great Firewall of China, but with the ability to maintain independence with an isolated intranet if needed.
But some officials think the voice that western countries will cut off Russia's network is very ridiculous, instead, the Russian government will do it automatically in emergency to eliminate the negative impacts on the nation.