Create Network Namespace with IPv6 connectivity via Hurricane Electric tunnel (no NAT66 needed)

ns-ipv6-no-nat.sh

#!/usr/bin/env bash

set -x

if [[ $EUID -ne 0 ]]; then
   echo "You must run this script as root."
   exit 1
fi

# Fill up IPv6 addresses for the veth pair.  Addresses must belong to the
# IPv6 block leased by Hurricane Electric.  For instance: 2001:XXXX::101/64.

VETH1_IPV6=         # IPv6 address for the host side.
VPEER1_IPV6=        # IPv6 address for the network namespace side.

# Clean up.
ip netns del ns-ipv6 &>/dev/null
ip li del veth1 &> /dev/null

# Create network namespace.
ip netns add ns-ipv6

# Create veth pair.
ip li add name veth1 type veth peer name vpeer1

# Setup veth1 (host).
ip -6 addr add ${VETH1_IPV6} dev veth1
ip -6 route add ${VPEER1_IPV6}/128 dev veth1
ip li set dev veth1 up

# Setup vpeer1 (network namespace).
ip li set dev vpeer1 netns ns-ipv6
ip netns exec ns-ipv6 ip li set dev lo up
ip netns exec ns-ipv6 ip -6 addr add ${VPEER1_IPV6} dev vpeer1
ip netns exec ns-ipv6 ip -6 route add ${VETH1_IPV6}/128 dev vpeer1
ip netns exec ns-ipv6 ip li set vpeer1 up

# Direct external traffic to VETH1 through VPEER1 (default gw).
ip netns exec ns-ipv6 ip -6 route add default dev vpeer1 via ${VETH1_IPV6}

# IP Forwarding.
sysctl -w net.ipv6.conf.all.forwarding=1

# Get into ns-ipv6.
ip netns exec ns-ipv6 /bin/bash --rcfile <(echo "PS1=\"ns-ipv6> \"")