Questions tagged [vpn]

VPN is the acronym for Virtual Private Network - a network type that uses a the Internet to provide remote networks or single machines with secure access to their organization's network avoiding expensive leased lines.

A VPN is a private network that uses a public network to connect remote sites or users. VPN use virtual connections routed through the Internet from the company's private network to the remote user or secondary site.

VPNs encapsulate data transfers using secure cryptographic methods and other security mechanisms to ensure that only authorized users can access the network and that the data cannot be intercepted.

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Should I use tap or tun for openvpn?

What are the differences between using dev tap and dev tun for openvpn? I know the different modes cannot inter-operate. What is the technical differences, other then just layer 2 vs 3 operation. Are there different performance characteristics, or…
Thomaschaaf
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Connecting to a remote server through a VPN when the local network subnet address conflicts with a remote network

This is a Canonical Question about solving IPv4 subnet conflicts between a VPN client's local network and one across the VPN link from it. After connecting to a remote location via OpenVPN, clients try to access a server on a network that exists…
John Russell
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64-bit Cisco VPN client (IPsec)?

Cisco VPN client (IPsec) does not support 64bit Windows. Worse, Cisco does not even plan to release a 64-bit version, instead they say that "For x64 (64-bit) Windows support, you must utilize Cisco's next-generation Cisco AnyConnect VPN…
mika
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How do you avoid network conflict with VPN internal networks?

While there's a wide variety of private non-routable networks across 192.168/16 or even 10/8, sometimes in being thoughtful of potential conflict, it still occurs. For example, I set up an installation OpenVPN once with the internal VPN network on…
jtimberman
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telnet counterpart for UDP

Is there anything that enables a "telnet-like" functionality for UDP? I know the difference between TCP and UDP, and why telnet itself won't work - but I'm wondering if there is something similar to the telnet client, from the end-user perspective.…
Dexter
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Checkpoint VPN Linux Client

Is there a Linux client for Checkpoint VPN? Preferably for Ubuntu?
Rubem Azenha
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Very low TCP OpenVPN throughput (100Mbit port, low CPU utilization)

I am experiencing extremely slow OpenVPN transfer rates between two servers. For this question, I'll call the servers Server A and Server B. Both Server A and Server B are running CentOS 6.6. Both are located in datacenters with a 100Mbit line and…
Elliot B.
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Under what circumstances is TCP-over-TCP performing significantly worse than TCP alone (2014)?

Many admins keep perpetuating - on ServerFault and elsewhere - how bad of an idea TCP-over-TCP is, e.g. in VPNs. That even the slightest packet loss will make one suffer from at least severe throughput degradation if not TCP meltdown, and that…
Nils Toedtmann
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IPsec for Linux - strongSwan vs Openswan vs Libreswan vs other(?)

Searching for IPSec and Linux one inevitably will be confronted with different solutions (see below) which all seem quite similar. The question is: where is the difference? I found these projects. All of them are open source, all are active (have a…
masgo
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OpenVPN client-to-client

When using a TUN (layer 3) OpenVPN server with client-to-client disabled, my clients can still talk to each other. The client-to-client config should prevent this according to the documentation: Uncomment out the client-to-client directive if you…
lobi
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Windows Advanced Firewall: What does "Edge Traversal" mean?

this should be a really simple one: In Advanced Windows Firewall on Windows Server 2008+, Properties > Advanced, what does "Edge Traversal" mean? I Googled it, of course, and was unable to come up with a concrete answer, and I was especially…
Django Reinhardt
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openconnect cannot connect to Anyconnect VPN group using -g

I am using openconnect to connect to a VPN. When starting the client as sudo openconnect -v -u anaphory vpn-gw1.somewhere.net, I am able to connect after entering the GROUP and Password. # openconnect -v -u anaphory vpn-gw1.somewhere.net […] XML…
Anaphory
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Mysterious misdirected Chinese traffic : How can I find out what DNS server an HTTP request used?

For the past week I've been getting a huge stream of traffic from a wide range of Chinese IP addresses. This traffic appears to be from normal people and their HTTP requests indicate that they think I'm: Facebook The Pirate Bay various BitTorrent…
Chris Sattinger
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How do I prevent TCP connection freezes over an OpenVPN network?

New details added at the end of this question; it's possible that I'm zeroing in on the cause. I have a UDP OpenVPN-based VPN set up in tap mode (I need tap because I need the VPN to pass multicast packets, which doesn't seem to be possible with tun…
Jason R
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How to connect to a Juniper VPN from Linux

The Windows users have a new client "Juniper Pulse" to connect to the Juniper VPN server. On Linux, what VPN client do we have to connect to that Juniper VPN, with maximum compatibility? Please mention the necessary parameters that have to be…
Déjà vu
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