Oracle OCI IPv6 autodiscovery

configure-ipv6.service

# /etc/systemd/system/configure-ipv6.service

[Unit]
Description=Configure IPv6 address and Add IPv6 Default Route via Script
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/configure_ipv6.sh
RemainAfterExit=true

[Install]
WantedBy=multi-user.target

configure_ipv6.sh

#!/bin/bash
# /usr/local/bin/configure_ipv6.sh

if [[ $EUID -ne 0 ]]; then
   echo "Error: This script must be run as root" 1>&2
   exit 1
fi

INTERFACE="enp0s6"

# find gateway
dhclient -6 $INTERFACE
output=$(rdisc6 $INTERFACE 2>/dev/null)
ipv6_gateway=$(echo "$output" | grep -oP 'fe80::[0-9a-f:]{1,39}')

if [[ -z "$ipv6_gateway" ]]; then
  echo "Error: Could not find IPv6 gateway address from rdisc6 output."
  exit 1
fi
echo "Found IPv6 gateway: $ipv6_gateway"

# set route
ip -6 route del default
ip -6 route add default via "$ipv6_gateway" dev "$INTERFACE"

if [[ $? -eq 0 ]]; then
  echo "Successfully added default IPv6 route via $ipv6_gateway on $INTERFACE."
else
  echo "Error: Failed to add default IPv6 route."
fi