Configuring IPv6 Passthrough for Padavan Router to Enable IPv6 for All Internal Hosts

China Telecom and CERNET commonly provide IPv6, but getting that IPv6 connectivity distributed correctly to devices behind a router is often where the setup goes wrong. This article records a working Padavan-based configuration for a K2 router so that internal devices can receive IPv6 properly.

One important prerequisite: if your ISP or upstream network does not actually provide usable native IPv6, changing router settings alone will not fix it. This guide assumes native IPv6 is already available on the WAN side.

Firmware address: padavan

Steps:

1. Enable native IPv6 support in the external network settings.
2. Configure the startup script for IPv6 passthrough.

Before You Start

• Your router is already running Padavan firmware and you can access the admin panel.
• Your ISP or campus network already provides native IPv6.
• You are willing to edit the startup script and reboot the router to validate the change.

Enabling Native IPv6 Support in External Network Settings

First, log in to the Padavan router at 192.168.123.1

Go to Advanced Settings –> External Network –> IPv6 Settings, and configure it as shown in the image below:

Configuring the Startup Script for IPv6 Passthrough

Next comes the IPv6 passthrough step. The idea is to place the required commands into the router startup script so the configuration is applied automatically after every reboot. Go to Advanced Settings –> Custom Settings –> Scripts –> Execute after router starts. Finally, add the following commands:

#ipv6 set
modprobe ip6table_mangle
ebtables -t broute -A BROUTING -p ! ipv6 -j DROP -i eth2.2
brctl addif br0 eth2.2
sysctl -w net.ipv6.conf.br0.accept_ra=2

After successful addition, it should look like this:

Restart Router and Check Computer’s IPv6

After restarting the router, connect a device to the router’s Wi-Fi and check its IP address. Use ipconfig on Windows, and ifconfig or ip a on macOS or Linux.

Use ping6 to confirm IPv6 connectivity:

ping6 ipv6.baidu.com

If the client receives a global IPv6 address and ping6 succeeds, the configuration is basically working.

Summary:

This article turns the Padavan IPv6 passthrough setup into a simple sequence: confirm native IPv6 upstream, enable IPv6 in the WAN settings, then persist the bridge-related commands in the startup script. Once that is in place, the router should continue applying the setup after reboot.

If IPv6 still does not appear on client devices, check the upstream IPv6 availability first, then verify the WAN IPv6 mode in Padavan, and only after that debug the script itself.