Time: November 21st, 2023
What is a
VPN
?
VPN, or
Virtual Private Network
, is essentially a virtualized internal dedicated line that can be understood as a simulated private network. Let's explore the definition of VPN and common troubleshooting approaches.
What is a
VPN
?
VPN
establishes a proprietary communication line between two or more enterprise internal networks located at different places on the internet using specialized encrypted communication protocols. It's akin to setting up a dedicated line without the need for physical cabling or similar physical infrastructure.
In simpler terms, if we were to explain
VPN
, it's essentially like a "lane within a lane" - similar to a "bus lane" on a city avenue. The distinction lies in the fact that the "lane" formed by a VPN isn't physically tangible; it's virtually created through technological means, hence the term "virtual". However, this
virtual private network
technology enables the establishment of a logical private "channel" between two computers over a shared network. It offers excellent confidentiality and immunity to interference, allowing both parties to engage in a secure and unrestricted
peer-to-peer
connection. This is why network administrators pay significant attention to it.
Defined as a temporary, secure connection over a public network (typically the internet),
VPN
creates a secure and stable tunnel through the chaotic public network. It serves as an extension of enterprise intranets. VPN tunnel protocols mainly include three types:
PPTP
,
L2TP
, and IPSec. Among these, PPTP and L2TP operate at the second layer of the
OSI model
, known as second-layer tunnel protocols, while IPSec is a third-layer tunnel protocol.
Why Does My
VPN
Crash? Common VPN Issues Explained
1. Error 691: "Access was denied because the username and/or password on the domain is invalid."
Typically occurs due to incorrect account credentials entered during
VPN
connection or insufficient permissions to use the VPN service. Each VPN account is usually limited to one computer. Check for duplicate logins with your username. If disconnected while in use, wait a few minutes before reconnecting. If the error persists, contact the network administrator.
2. Error 691: "Port was disconnected."
Some routers have limited support for
VPN
, leading to various issues like Error 691, limited connections, frequent disconnections, and occasionally, Error 800. This is often due to routers using
NAT
, preventing VPN protocols from penetrating. Try temporarily disabling the system firewall and retrying. For occasional occurrences, redial a few times or restart the computer and
router
before retrying. If using LAN or internet via a router, request the network administrator to open
UDP
ports 1701-1704 on the server or router.
3. Error 721: "Remote computer is not responding."
Likely caused by network latency. Attempt multiple connections or try the following steps: Navigate to the registry editor, locate the
WAN
Miniport (
PPTP
)
adapter
, and create a
DWORD
value named Validate Address set to '0' to disable it. Restart your computer.
4. Error 742/741: "The remote server does not support encryption."
In
VPN
properties, select "No encryption allowed" or a similar option in the security settings to resolve this issue.
5. Error 800: "Unable to establish
VPN
connection. VPN server unreachable."
Similar to Error 691 and may benefit from temporarily disabling the system firewall or restarting the
router
.
Is it illegal to use a
VPN
?
Using a
VPN
itself is not illegal. However, the legality of VPN usage depends on how it is employed, and the activities conducted through it. VPNs are primarily tools designed to enhance privacy and security on the internet by encrypting data and masking
IP
addresses. They are commonly used for legitimate purposes such as securing sensitive information, accessing region-restricted content, or ensuring anonymity while browsing.
While using VPNs may appear harmless and anonymous, it is worth noting that they could be used for illicit purposes like cybercrime, hacking, spreading malware, financial crimes, etc., or bypassing geographical barriers for committing unlawful acts. So, it's regulated in some countries. For instance, in China, the usage of VPNs is limited with certain governmental controls imposed on them.
Conclusion
This article explains “
what is a
VPN
”, why my VPN crashed, and the legal risks of using a VPN, and hopefully, it will be helpful to you.
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