https://github.com/m13253/userland-ipip
Userland IPIP + IP6IP (6in4) / IPIP6 + IP6IP6 tunnel for Linux
https://github.com/m13253/userland-ipip
6in4 ipip ipv6 linux networking tunnel
Last synced: 2 months ago
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Userland IPIP + IP6IP (6in4) / IPIP6 + IP6IP6 tunnel for Linux
- Host: GitHub
- URL: https://github.com/m13253/userland-ipip
- Owner: m13253
- License: gpl-3.0
- Created: 2020-03-07T08:56:11.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2020-08-05T04:46:28.000Z (almost 5 years ago)
- Last Synced: 2025-03-28T04:34:51.251Z (3 months ago)
- Topics: 6in4, ipip, ipv6, linux, networking, tunnel
- Language: Go
- Homepage:
- Size: 40 KB
- Stars: 26
- Watchers: 2
- Forks: 3
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-starred - m13253/userland-ipip - Userland IPIP + IP6IP (6in4) / IPIP6 + IP6IP6 tunnel for Linux (linux)
README
# userland-ipip
Userland IPIP + IP6IP (6in4) / IPIP6 + IP6IP6 tunnel for Linux
userland-ipip sets up either an IPIP + IP6IP (6in4) tunnel, or an IPIP6 + IP6IP6
tunnel between two hosts.
## Features
- userland-ipip reduces headache when you find that a `type ip6tnl mode any`
tunnel is not as reliable as you assume. Either IPv4 or IPv6 payload drops
silently at some magic time. You tried various methods, only to find that a
system reboot can solve the problem auto-magically.
- userland-ipip calculates `local` address automatically, saving you time to
write scripts for an DHCP-assigned host.
- userland-ipip also solves the problem when you want to fragment your tunnel.
(i.e. inner MTU larger than outer MTU.)
## Building
1. Download Go compiler. The newer version, the better.
2. Type
```bash
./build.sh
```
3. Pick your fruit at `./build/ipip`.
## Usage
```
Usage: ipip [-4 | -6] dev DEVICE [local ADDRESS] remote ADDRESS [mtu MTU]
Userland IPIP + IP6IP (6in4) / IPIP6 + IP6IP6 tunnel for Linux.
This program establishes IPIP and IP6IP (6in4) tunnel, or IPIP6 and IP6IP6
tunnel on a TUN device.
Options:
-4 use IPv4 to resolve addresses.
-6 use IPv6 to resolve addresses.
otherwise, IPv6 will be tried first, then IPv4.
Project web page: https://github.com/m13253/userland-ipip
```
## Example
Please change the names and the addresses below to suit your needs.
On the first machine (e.g. fox.localdomain)
```bash
sudo ip tuntap add mode tun name tun-rabbit
sudo ip address add 10.0.0.1 peer 10.0.0.2/32 dev tun-rabbit
sudo ip address add fd00:cafe::1 peer fd00:cafe::2/128 dev tun-rabbit
sudo ./build/ipip dev tun-rabbit remote rabbit.localdomain mtu 1460
```
On the second machine (e.g. rabbit.localdomain)
```bash
sudo ip tuntap add mode tun name tun-fox
sudo ip address add 10.0.0.2 peer 10.0.0.1/32 dev tun-fox
sudo ip address add fd00:cafe::2 peer fd00:cafe::1/128 dev tun-fox
sudo ./build/ipip dev tun-fox remote fox.localdomain mtu 1460
```
To stop the tunnel, press `Ctrl-C`, then type
```bash
sudo ip link delete tun-rabbit
```
or
```bash
sudo ip link delete tun-fox
```
## Preventing “connection refused”
You may find a lot of “connection refused” on the screen. They are caused by
the remote machine sending ICMP errors to us.
It is suggested to block these packets to save bandwidth. A dirty but effective
method is to use iptables on both sides running userland-ipip:
```bash
sudo iptables -A OUTPUT -d [PEER IPv4 ADDRESS] -p icmp --icmp-type 3/3 -j DROP
sudo ip6tables -A OUTPUT -d [PEER IPv6 ADDRESS] -p icmpv6 --icmpv6-type 1/4 -j DROP
```
## Use userland-ipip with systemd
I don't provide a systemd service file out-of-the-box, since you may want to
write one systemd service for each tunnel you want to create.
Here is a template that you can modify based on:
```systemd
[Unit]
Description=Userland IPIP for rabbit.localdomain
Documentation=https://github.com/m13253/userland-ipip
After=network.target
[Service]
ExecStartPre=-/usr/bin/env ip tunnel delete tun-rabbit
ExecStartPre=/usr/bin/env ip tuntap add mode tun name tun-rabbit
ExecStartPre=/usr/bin/env ip address add 10.0.0.1 peer 10.0.0.2/32 dev tun-rabbit
ExecStartPre=/usr/bin/env ip address add fd00:cafe::1 peer fd00:cafe::2/128 dev tun-rabbit
ExecStart=/path/to/ipip dev tun-rabbit local fox.localdomain remote rabbit.localdomain mtu 1460
ExecStopPost=/usr/bin/env ip tunnel delete tun-rabbit
Restart=always
RestartSec=3
Type=simple
[Install]
WantedBy=multi-user.target
```
## Use userland-ipip with `/etc/network/interfaces`
```conf
auto tun-rabbit
iface tun-rabbit inet static
address 10.0.0.1
pointopoint 10.0.0.2
pre-up ip tuntap add mode tun name $IFACE
up /path/to/ipip dev $IFACE local fox.localdomain remote rabbit.localdomain mtu 1460 &
post-down ip link del $IFACE
iface tun-rabbit inet6 static
address fd00:cafe::1/128
up ip route add fd00:cafe::2 dev $IFACE metric 256
```
## License
This program is released under GNU General Public License version 3 or later.
I hope this program can be useful to you. But I provide **absolutely no
warranty**. In case the program causes any damage due to malfunctioning, I might
be willing to diagnose and fix the problem, but it is not my obligation to
do so.