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How the media have changed Mankind, and Manchestovo has changed the media over the past couple of thousand years
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Website promotion: how to get real results
After the work on SEO-optimization, the sales department was “cut off” by inappropriate calls. The contextual contractor regularly “masters” the budget, but there are no more applications. The PR man…

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protocols that use checksum calculation

PPTP VPN

This protocol allows you to implement a secure point-to-point connection by creating a tunnel in an insecure network.

The work of PPTP is to implement PPP frames in IP packets for transferring them to any IP network, including the Internet. In addition, this technology can be used to create a tunnel between local networks.

A TCP connection is used to service the created PPTP tunnel.

Brief specification
The protocol specification was published in 1999 in RFC2637, but the IETF community has not ratified it.
Less secure than IPSec, PPTP establishes a PPP session using the GRE protocol. The 1723 TCP port is used to control and initiate the GRE connection. Redirecting PPTP to the firewall is difficult because the protocol requires two sessions to be established simultaneously. Continue reading

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