${toc}

# Install Tayga

apt update
apt install -y tayga

# Configure sysctl / ensure IPv4 and IPv6 forwarding is enabled

For Tayga to work properly, you must have both IPv4 and IPv6 forwarding enabled.

Since the NAT64 server will also function effectively like a router, the sysctl config that's generated below will:

- Disables most IPv6 router advertisement settings (SLAAC)
- Disables the main `accept_ra` switch
- Disables accepting default route advertisements
- Disables interface IPv6 auto-configuration
- Enables accepting MTU size advertisements, since MTU is very important
- Disables IPv4/v6 redirects
- Adjusts the IPv6 MTU for the primary interface to match the VPN's MTU (1420 for wireguard).

## Manually enable forwarding

# Not necessary, but you may wish to run the below commands to enable IPv4 / IPv6 forwarding immediately.
sudo sysctl -w net.ipv6.conf.all.forwarding=1
sudo sysctl -w net.ipv4.conf.all.forwarding=1
sudo sysctl -w net.ipv4.ip_forward=1

## Generating a sysctl config (`95-privexnet.conf`)

# DEFAULT_IFACE should be set to the name of your PRIMARY INTERFACE, i.e. the one
# with the server's public IPv4/v6 address(es).
# IFACE_MTU should be set to match your VPN's MTU. For wireguard, this is typically 1420
DEFAULT_IFACE="eth0"
IFACE_MTU="1420"

sudo tee /etc/sysctl.d/95-privexnet.conf <<EOF
#########
# Privex SYSCTL Config Options
#########

# Enable IP forwarding for IPv4 and IPv6
net.ipv6.conf.all.forwarding=1
net.ipv4.conf.all.forwarding=1

net.ipv6.conf.${DEFAULT_IFACE}.forwarding=1
net.ipv4.conf.${DEFAULT_IFACE}.forwarding=1

net.ipv4.ip_forward=1

####
# Disable IPv6 router advertisements that could potentially cause problems
####

# Main "accept router advertisements" flag - affects all other RA settings
net.ipv6.conf.all.accept_ra=0
net.ipv6.conf.${DEFAULT_IFACE}.accept_ra=0
# DO NOT accept advertisements for default router
net.ipv6.conf.all.accept_ra_defrtr=0
net.ipv6.conf.${DEFAULT_IFACE}.accept_ra_defrtr=0
# DO NOT attempt to auto-configure via SLAAC or RA's
net.ipv6.conf.all.autoconf=0
net.ipv6.conf.${DEFAULT_IFACE}.autoconf=0
# ACCEPT MTU advertisements from RA's - since MTU is very important
net.ipv6.conf.all.accept_ra_mtu=1
net.ipv6.conf.${DEFAULT_IFACE}.accept_ra_mtu=1

####
# Misc. Network Settings
####

# do not accept redirects
net.ipv6.conf.all.accept_redirects=0
net.ipv4.conf.all.accept_redirects=0
net.ipv6.conf.eth0.accept_redirects=0
net.ipv4.conf.eth0.accept_redirects=0

# adjust default iface to use same MTU as wireguard for IPv6
net.ipv6.conf.${DEFAULT_IFACE}.mtu=${IFACE_MTU}

EOF

## Importing / reloading the sysctl configs

# Load all sysctl configs
sudo sysctl -p
# Ensure sysctl actually read the privexnet config by specifying it
sudo sysctl -p /etc/sysctl.d/95-privexnet.conf

-------------

# Configuration Files

## default/tayga

`/etc/default/tayga`

# Defaults for tayga initscript
# sourced by /etc/init.d/tayga
# installed at /etc/default/tayga by the maintainer scripts

# Change this to "yes" to enable tayga
RUN="yes"

# Configure interface and set the routes up
CONFIGURE_IFACE="yes"

# Configure NAT44 for the private IPv4 range
CONFIGURE_NAT44="yes"

# Additional options that are passed to the Daemon.
DAEMON_OPTS=""

# IPv4 address to assign to the NAT64 tunnel device
IPV4_TUN_ADDR="192.168.255.1"

# IPv6 address to assign to the NAT64 tunnel device
IPV6_TUN_ADDR="2a07:e01:ffff::2"

## tayga.conf

`/etc/tayga.conf`

tun-device nat64

# Tayga's IPv4 address (doesn't really matter)
ipv4-addr 192.168.255.1

# Tayga's IPv6 address (to be routed to)
ipv6-addr 2a07:e01:ffff::2

# V6 Prefix to use for the IPv4 internet
prefix 64:ff9b::/96

dynamic-pool 192.168.0.0/16
data-dir /var/spool/tayga

## Networking Config

`/etc/netplan/50-cloud-init.yml`

network:
    version: 2
    ethernets:
		# eth0 = Public Internet adapter
		# Must have IPv4, but doesn't require IPv6
        eth0:
            addresses:
            - 185.130.44.60/27
            gateway4: 185.130.44.33
            accept-ra: no
            match:
                macaddress: 1a:76:89:d4:09:b1
            nameservers: &id001
                addresses:
                - 2a07:e00::333
                - 8.8.4.4
                - 1.1.1.1
                search:
                - privex.bz
            set-name: eth0
		# eth1 - NAT64 IPv6 Gateway Adapter
		# Should have both a "public" IPv6 address (::1), used for accessing the server
		# and the "gateway" IPv6 (::2) used for routing the NAT64 prefix into
        eth1:
            addresses:
            - 2a07:e01:ffff::1/64
            - 2a07:e01:ffff::2/64
            gateway6: 2a07:e01:ffff::f
            match:
                macaddress: a6:08:61:c3:e5:e1
            nameservers: *id001
            set-name: eth1

# Enabling and starting Tayga

systemctl enable tayga
systemctl restart tayga

# Adding routes

## Cisco

ipv6 route 64:FF9B::/96 2A07:E01:FFFF::1 name NAT64
ipv6 route 64:FF9B::/96 2a07:e02:10ff::2 name NAT64-CA

## Linux CLI

ip -6 route add 64:ff9b::/96 via 2a07:e02:10ff::2 dev br0 metric 10 pref high

ip -6 route add 64:FF9B::/96 via 2a07:e00::64:64 dev eth0

## Netplan

NOTE: On our Vultr regions, the route should be added to `/etc/netplan/30-bridge.yaml`

routes:
	# 64:ff9b::/96 via 2a07:e02:10ff::2 dev br0 metric 10 pref high
	- to: 64:ff9b::/96
	  via: 2a07:e02:10ff::2
	  metric: 10