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Questions tagged [tun]

The tag has no usage guidance.

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0answers
50 views

write into a tun interface and forward traffic to another computer

I have the following setup. An application on machine A creates an IP packet which is captured by the tun1 interface. I have added the route using the command : sudo route add -host 10.129.131.220 ...
1
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1answer
242 views

OpenVPN persist-tun option - what's the point?

According the OpenVPN 2 Cookbook: The persist-tun and persist-key options are used to ensure that the connection comes back up automatically if the underlying network is disrupted. These ...
0
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1answer
122 views

Multiqueue tun/tap interface

I am trying to understand how Multiqueue tuntap interface works. Following the instructions provided at: https://www.kernel.org/doc/Documentation/networking/tuntap.txt I was able to create multiple ...
2
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1answer
151 views

IPv6 on Linux tun/tap: NDP not working

I am working on an old code that used to connect different IPv6 devices over a different kind of network (a powe line netwrok, PLC, which is quite similar to 802.15.4). To do that, it created Linux ...
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0answers
112 views

Forward vpn traffic from tun0 to tun1

There is the following connection scheme client 1 <-> server 1 (tun 0) <-> server 2 (tap 0) <-> client 2. Server 1 and 2 are located on the same host and used for packet forwarding using ...
2
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1answer
2k views

OpenVPN TAP vs TUN in parallel

I have a few questions about our existing OpenVPN server setup and a requirement that we have to expand our access. Our current setup is as follows: 1 OpenVPN server (in TAP mode) Multiple VM ...
0
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1answer
480 views

How to set up single client TAP/TUN on the client for my OpenVPN?

My laptop OpenVPN client establishes a TAP device. My client config is TUN, though. This devices shows under ifconfig /ALL with the IP 10.8.0.6 and a subnetmask of 255.255.255.252. (!!!) This ...
0
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1answer
922 views

Can the inet address assigned to P-t-P tun interface be used for a client inet address if the server runs out of all addresses within a subnet?

I have an OpenVPN server with an Inet address 10.8.0.1 serving the subnet 10.8.0.0/24. I have two clients connected to this server and the status log (/etc/openvpn/openvpn-status.log)reads as follows: ...
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1answer
1k views

Issues setting up TINC on Mac OSX 10.12.2

I have TINC setup on a few linux boxes and they are working great. linux001 (static ip vps - 10.0.0.1) macosx002 (connects to linux001 - 10.0.0.2) linux050 (connects to linux001 - 10.0.0.50) I also ...
0
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1answer
75 views

OpenVPN allows some users to jump to other hosts in the LAN

All users can connect to host where OpenVPN runs but some users can jump to other hosts in the LAN. For example, foo user can reach host 10.2.0.1/32 (where OpenVPN runs) and hosts at 10.0.0.0/24 but ...
0
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1answer
911 views

openvpn - Why do I have 2 tun interfaces on my server?

I have just configured watching this Hak5 video I found on Youtube. But what is bothering me is that why do I have two tun interfaces on my server ? Namely-: tun0 Link encap:UNSPEC HWaddr 00-...
0
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1answer
157 views

Why is my host not receiving packets sent across tun0?

I have a tun0 interface set up which allows packets to be sent as such: HOST (aaaa::1) ----> tun0 ----> SLIP ----> Router (aaaa::200:0:0:1) The router receives the packets, and can send back a ...
0
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1answer
670 views

How do I route traffic over the a tun0 device (IPSec VPN connection)?

I've set up an IPSec VPN tunnel between my laptop and work. The tunnel gets established, but routing does not. The relevant part of ifconfig is : eth0 Link encap:Ethernet HWaddr d4:be:d9:6f:a7:...
0
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1answer
30 views

Endpoint to security gateway tunnel

I want to establish a connection between the client and the proxy server through a VPN tunnel in android device. I want to do this at layer 2 or 3 , where a packet can captured and encrypted. Please ...
5
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3answers
559 views

How do VPN servers/clients avoid routing their own remote connection packets through themself?

I am trying to conceptualise how networking works under the hood for linux VPNs which use TUN interfaces. My current best guess is as follows (please correct me): Connection established to remote ...
1
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0answers
534 views

Direct all traffic between Eth0:1 interface and VPN Tun0

If answered correctly this question will show you how to link a 2nd public IP address on a machine to a VPN server tunnel on that machine, so that the remote VPN client (running a server), sees this ...
0
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1answer
217 views

OpenVPN - connect server as client to itself

I have tried to setup a small openvpn network but I ran into one big problem. I have a server and a machine at home. So I created a openvpn server on my machine and a configured the client on the ...
1
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1answer
764 views

Prevent IP Spoofing on OpenVPN tun

I have a question regarding IP Spoofing and authentication. I have an OpenVPN server in TUN mode with many untrusted clients in the same VPN network, and I was wondering if one client is able to spoof ...
0
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1answer
627 views

/dev/net/tun exists, but OpenVPN is refussing to find it

I'm currently configuring an OpenVPN client on an arm microprocessor running debian squeeze, however I'm running into problems. As the below shows, /dev/net/tun exists: debarm:~# whoami root debarm:~...
9
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1answer
7k views

How to create /dev/tun device inside unprivileged LXC container?

This question is similar to No tun device in lxc guest for openvpn . The LXC has evolved and the unprivileged LXC containers were introduced recently that offer another layer of security against ...
1
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1answer
4k views

What exactly happens to packets written to a TUN/TAP device?

I'm trying to send packets to an application listening on eth0 from machine's user-space as if they were coming from a remote machine. What I can't seem to find good documentation for is the exact ...
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0answers
82 views

OpenVPN tunnel not able to support secure connect request

In CentOS 7 host we have installed openvpn package and did create an tunnel using OpenVPN tunneling for eth9 and tap9. Everthing work fine for unsecure connection but when we try to connect to server ...
2
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2answers
862 views

Use OpenVPN tun device for specific request

I have setup an OpenVPN connection with the route-nopull configuration. So now no special routes have been added to the client's configuration and only a TUN device is created, like so: tun0 ...
0
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1answer
154 views

Setup openvpn as interface device only

I just setup OpenVPN client using this guide on The Geek Stuff But now (somewhat as expected) all my traffic is routed through the VPN. I actually just want to set up the interface device. Does ...
0
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2answers
3k views

OpenVPN Tunnel between two LANs, traffic dropped on the way?

I'd like to create a OpenVPN Tunnel between to LANs 192.168.1.0/24 and 192.168.2.0/24. However somehow packets entering the tunnel on one side don't come out of the other side ... The following ...
0
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2answers
4k views

openvpn connection has established but cant ping the server

I have a openvz vps and setup a openvpn server, and I successfully connect to the server in my ubuntu 14.10 client. server.conf: port 1199 proto udp dev tun ca ca.crt cert server.crt key server.key ...
0
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1answer
493 views

TCP RST from telnet/ssh daemons when connecting from openvpn

I have LAN_1 and LAN_2 interconnected with an openvpn tunnel terminated ona pair of SOHO routers running busybox. One of the vpn purpose is to allow clients on both LAN_1 and LAN_2, to administer the ...
1
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0answers
444 views

TUN/TAP VPN no internet connection

I have set up a tun/tap vpn to a VPS. For this, I created a 10/24 network and gave the server the IP 10.0.0.100 and my client got 10.0.0.200. I can now successfully ping the server / access my mail ...
3
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1answer
8k views

iptables: access connected openvpn client from the LAN with the VPN server

I have what is essentially a routing problem, and I'm not familiar enough with routing and iptables to effectively troubleshoot and set up my network needs. What's working I have an openVPN network ...
1
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1answer
3k views

How to make Tun module running at linux start

i installed Tun using: modprobe tun then did: lsmod | grep tun tun 83840 0 Please how to make Tun running at reboot? This is written on Hamachi website: ...Then add tun to ...
0
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1answer
635 views

Unbridged tap device

Good UTC evening! I've created a tap0 device on my host, it looks like: tap0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 inet 10.0.0.1 netmask 255.255.255.0 broadcast 10.0.0.255 ...
0
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1answer
436 views

bridge on openVPN client

I have some problem with setting up what i call a "remote entry point" (i'm sure ther is a real name for this) First things First : Here is my setup : ||==============================================...
0
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1answer
678 views

Is there a way to allow specific permissions to a non-root user?

I have a program that, at some point, create/destroys tun/tap virtual adapters. Obviously, for these specific operations this program requires root privileges. According to the program ...
0
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1answer
411 views

Where is the userspace used by TUN/TAP?

When I put data on a wire in qemu what sets the upper limit on the rate of data I can transmit? The situation is I set up two machines A and B create two tap interfaces openvpn --mktun --...
0
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1answer
3k views

Simple iptables port forwarding with masquerading not working

I'm trying to set up a simple VPN server on EC2 (Ubuntu 12.04) with the Android example ToyVpnServer. Its instructions: // There are several ways to play with this program. Here we just give an // ...
5
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2answers
10k views

openvpn: connection established, can't ping server tun interface (debian server, windows & os x clients)

My goal: I want to set up openVPN on a vServer from the company netcup, running Debian squeeze. I only want a VPN connection from client to server; clients should not be able to see each other, also ...
5
votes
2answers
5k views

How can I configure openvpn to proxy traffic only for processes that bind to the tun interface?

I'm trying to configure openvpn so that only traffic from certain processes goes over the vpn, but those processes could connect to anywhere. I'm trying to do that by having openvpn not do any route ...
4
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1answer
2k views

Why doesn't TUN device have BROADCAST flag?

When creating a TUN device in Linux, on my machine the created TUN device has following flags: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> Clearly MULTICAST is listed in there but not BROADCAST. ...
0
votes
1answer
3k views

How's the routing done in a very simple OpenVPN setup?

I've entirely configured (remotely) a Debian GNU/Linux dedicated server hosted in a professional capacity and I've got a network routing question (which AFAICT precisely fits the FAQ of serverfault). ...
4
votes
1answer
1k views

Forward IP packets to tunnel device

I have created an tunnel device using ip tuntap add dev tun0 mode tun user 0 group 0 I then assign it an ip address 192.168.0.1/22 ifconfig tun0 192.168.0.1 netmask 255.255.252.0 On my ...
9
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1answer
1k views

Forwarding traffic from TUN device (C++ backend) to the default gateway

The following problem is just a piece of the bigger solution I have a problem with. All other elements seem working so far, so I'll try to describe very small piece which I have problem with. I've ...
3
votes
1answer
2k views

Route packets from one VPN to another

I have two OpenVPN servers (10.8.0.0 and 10.9.0.0) set up on my OpenSUSE server. Within one network, each computer is visible to any other one, but I'd like to make it so that computers are visible ...
3
votes
3answers
20k views

How do I enable TUN/TAP forwarding?

I have a program which writes packets (destination address 10.3.0.2) to the TUN/TAP interface. Network: host1|tun0----eth1(10.3.0.1)|-------------------host2|eth1(10.3.0.2)| Wireshark captures ...
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8answers
2k views

opvnvpn: addressing nodes in LAN-behinds

I've setup an openvpn server which i can access remotely, once it is connected, it creates a tun0 device on both server and client with virtual ip 10.15.119.x. the openvpn server is itself 10.15.119.1....
2
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2answers
4k views

openvpn: after changing to server mode, client does not create TUN device

I had a previously working configuration with the config files used in a previous question However, I've changed this now to the following configuration using server mode, everything on the logs seem ...
2
votes
1answer
2k views

IP Packet Capture/Manipulation via TUN/TAP

I'm trying to capture and manipulate incoming IP packets (via eth0 interface) by using a TUN device (since I'm only concerned with IP layer). The first step I think is 1:1 packet forwarding from eth0 ...
1
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2answers
5k views

How to configure a tun interface on Linux for SSH port forwarding?

I am trying to forward port 139 from a Windows machine to my Ubuntu SSH server on a tun interface with the ip address 10.0.0.1. This is so that I can access the windows shares on the machine on my ...
0
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1answer
940 views

why tun interface in openvpn

can anyone tell me the use of tun interface in openvpn? as far as i read, it is used to tunnel all the traffic from the PC over the ssl tunnel. But incase of VPN, i suppose all the traffic initiated ...
4
votes
1answer
10k views

OpenVPN Cannot allocate TUN/TAP dev dynamically

OpenVPN clients work fine when they're started by /etc/init.d/openvpn for the first time, but they can't reconnect if the master server is restarted. This is the error I get in syslog: ovpn-openvpn[...
6
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2answers
6k views

OpenVPN with iptables and a tun interface

With an openvpn tunnel that uses a tun device, what iptables rules allow the encapsulated traffic through and what rules control the packets after encapsulation? Basically, I am wondering how the ...