Questions tagged [tap]

87 questions
110
votes
11 answers

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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11
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2 answers

Ping not working from tap interface attached to bridge interface with ip on same subnet as that of bridge to outside

My requirement is to create a multiple tap interfaces, each with ip address on same subnet. I tried this by creating a bridge br0 (192.168.1.199) ___________|_____________________________________ | | …
ramz
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10
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2 answers

How can I setup OpenVPN with IPv4 and IPv6 using a tap device?

I've managed to setup OpenVPN for full IPv4 connectivity using tap0. Now I want to do the same for IPv6. Addresses and network setup (note that my real prefix is replaced by 2001:db8): 2001:db8::100:0:0/96 my assigned IPv6…
Lekensteyn
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9
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2 answers

ARP reply vanishes from br0 to tap0 using OpenVPN in bridging mode

I have setup a linux box (on an esxi5) which acts as an OpenVPN server. the server is configured to use bridging for the clients, which essentially works, with one exception. If the client pings some machine on the network which is not the server…
fen
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6
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1 answer

Cannot ioctl TUNSETIFF tap0: Device or resource busy (errno=16)

I'm having this weird issue that when I run bridge-start together with openvpn, the service won't start. If I don't let openvpn run bridge-start, and add the necessary interfaces (tap0, br0) manually (or run bridge-start from the shell) and I…
Lethargos
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4
votes
2 answers

OpenVPN Linux Client does not bring up tap0 interface

I have an OpenVPN client on Linux connecting to an OpenVPN server. The server assigns IPs via DHCP, thus I connect using the tap interface rather than the tun interface. OpenVPN connects, authenticates, chats with the server, and grabs a cup of…
Chris
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4
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3 answers

Assign static IPs to tap clients in pfSense's OpenVPN server

I am trying to set up a pfSense server with OpenVPN. The OpenVPN will use the tap interface, tun clients are no option for us. The LAN network is 10.0.0.0/24, the pfSense machine is 10.0.0.10 and clients DHCP range is currently…
Izzy
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4
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3 answers

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 these packets from interface tun0 but they are not…
rafal
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3
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1 answer

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 queues. However, I don't know how to check the…
Deys Nima
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3
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1 answer

Openvpn tap interface configuration gets self assigned IP

I have a strange misconfiguration on my openvpn tap network. Clients can connect and get there IP address in 192.168.42.x as intended, but after few seconds another address gets assigned to it, self-assigned this time (169.254.x.x). The problem it…
vitaminwater
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3
votes
1 answer

Add persistent bridge and tap in ubuntu 20.04 server

I'm trying to create a bridge whose interface is a tap, both with static IPs, and have them persist across reboots. In Ubuntu 14.04.6 LTS, this could be accomplished by editing /etc/network/interfaces as such: auto br0 iface br0 inet static …
Leshawn Rice
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3
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0 answers

How to migrate OpenVPN architecture TAP to TUN

I did a tunnel system with OpenVPN to let a distant client act like a private network client to access private resources. It uses a client on the private network as a gateway. DistantClient <-> OpenVPN server <-> PrivateNetworkClient It works with a…
Doubidou
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3
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2 answers

Windows: Send all network traffic from script/app through specific TAP adapter

I have created a script in Node.js to remotely manage a server. To work the script needs to be connected to a VPN. The VPN it needs to connect to is different from the one I want Windows to use. Both VPNs use OpenVPN. I have successfully created two…
2
votes
1 answer

Forwarding ICMP response to TAP interface

I am trying to do a test where I forward ICMP responses to a TAP interface. I created a TAP interface and assigned it the address 10.0.4.1/24. My linux setup uses the interface enp0s3 as the default option. To forward any ICMP response to the TAP…
Jake
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2
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1 answer

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 servers with host machine physically connected to the…
Adam Blalock
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