IPv6 (tutorial)

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Internet Protocol version 6 (IPv6) is a network layer IP standard used by electronic devices to exchange data across a packet-switched internetwork. It follows IPv4 as the second version of the Internet Protocol to be formally adopted for general use.

There are too many devices in the world for 32-bit (232, or 4,294,967,296) IP addresses to be sufficient.
The next version of the TCP/IP protocol, IPv6 offers 128-bit address space, or 2128 (≈ 3.4 x 1038) IP addresses; this is approximately 5×1028 addresses for each of the roughly 6.5 billion people alive today, or about 57 billion addresses for each gram of matter in the Earth.

Keep in mind it can be dangerous to enable IPv6 without also having a firewall on each client that handles IPv6 packets, or having ip6tables on your router to filter incoming connections. ip6tables is NOT included by default with DD-WRT, which means your clients will be directly exposed to the Internet once you have enabled IPv6.

Contents

Prerequisites

  • DD-WRT compatible router
  • Knowledge about the Command Line
  • Knowledge about the ip command
  • DD-WRT version 22 prefinal 5 minimum with distribution voip or standard only
    • IPv6 does NOT WORK on all versions of DD-WRT version 24. Version 24 sp1 stable has been verified to work with IPv6.
  • IPv6 enabled thru the GUI section Administration/Management/Router Management/Ipv6
  • Enabling jffs would be helpful (optional)

IPv6 on your LAN

Overview

If you already have a working IPv6 router or are not interested in routing IPv6 traffic out of your LAN, your main concern is to allow your wireless clients traffic pass the to the wired side.

When your DD-WRT box is your IPv6-router, see other solutions below for 6to4 tunneling solutions.

Enabling IPv6 Support

On the Administration>Management page, enable IPv6 and radvd.

Configuring Radvd (if your DD-WRT box is NOT your IPv6-router)

Radvd is similar to a DHCP server. It advertises your IPv6 prefix to the local network, so that a new client can generate its own IP address. This config tells radvd to get an IPv6-address from the wired side, and properly announce it to the LAN (br0).

Copy the following into your radvd settings box:

interface br0 {
   AdvSendAdvert on;
   prefix 0:0:0:1::/64 {
    AdvOnLink on;
    AdvAutonomous on;
   };
};

6to4 Setup

Overview

6to4 is a mechanism which assigns a large block of IPv6 addresses to every IPv4 address on the Internet. You can use 6to4 with DD-WRT to give every computer on your network a globally-accessible IPv6 address without the need to configure explicit tunneling. This should be the simplest method to add IPv6 to your entire network.

Important Reminders :

  • In order to use ipv6, you need the Standard or VoIP version of DD-WRT, as these are currently the only ones which support both IPv6 and radvd.
  • The detailled configuration steps are targeted toward users with a basic DHCP connection for the WAN part. So, if using PPPoE will require replacing vlan1 with ppp0 in each instance. Other connection types will vary.
  • When using DD-WRT standard on a router with 4MB Flash, there is no space available for jffs.
  • This guide only relies on nvram variables, so that jffs is not needed.
  • The configuration shown below has been verified to work properly on v24 sp1 stable (standard)

Enabling IPv6 Support

On the Administration>Management page, enable IPv6 and radvd.

Configuring Radvd

Radvd is similar to a DHCP server. It advertises your IPv6 prefix to the local network, so that a new client can generate its own IP address. This config tells radvd to get a 6to4 prefix from the WAN side (vlan1) and announce it to the LAN (br0)

Copy the following into your radvd settings box:

interface br0 {
   MinRtrAdvInterval 3;
   MaxRtrAdvInterval 10;
   AdvLinkMTU 1280;
   AdvSendAdvert on;
   prefix 0:0:0:1::/64 {
    AdvOnLink on;
    AdvAutonomous on;
    AdvValidLifetime 86400;
    AdvPreferredLifetime 86400;
    Base6to4Interface vlan1;
    AdvRouterAddr on;
   };
};

Startup Script

This startup script acquires your current IPv4 address and uses it to calculate a 6to4 IPv6 address. It then creates the tunnel interface, configures a route, and assigns the address. Afterwards, it sends radvd a SIGHUP so that it will become aware that the prefix has changed.

Go to Administration>Diagnostics or Administration>Commands in v24 sp1, copy the following into the big box, and hit "Save Startup".

insmod /lib/modules/`uname -r`/ipv6.o
sleep 5
radvd -C /tmp/radvd.conf start
sleep 5
WANIP=$(ip -4 addr show dev vlan1 | awk '/inet / {print $2}' | cut -d/ -f1)
if [ -n "$WANIP" ]
then
 V6PREFIX=$(printf '2002:%02x%02x:%02x%02x' $(echo $WANIP | tr . ' '))
 ip tunnel add tun6to4 mode sit ttl 255 remote any local $WANIP
 ip link set tun6to4 mtu 1280
 ip link set tun6to4 up
 ip addr add $V6PREFIX:0::1/16 dev tun6to4
 ip addr add $V6PREFIX:1::1/64 dev br0
 ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4
 kill -HUP $(cat /var/run/radvd.pid)
fi

6to4 on current builds (after v24 sp1)

Pandora-Box got a script that works on current builds of v24. This has been successfully implemented on Eko 13309 big (which does not come with ipv6, so you must use "ipkg install kmod-ipv6" to get it to work.

The scripts are as follows:

in Administration, under IPv6/RaDVD config:

 interface br0 { 
 MinRtrAdvInterval 3; 
 MaxRtrAdvInterval 10; 
 AdvLinkMTU 1280; 
 AdvSendAdvert on; 
 prefix 0:0:0:1::/64 { 
 AdvOnLink on; 
 AdvAutonomous on; 
 AdvValidLifetime 86400; 
 AdvPreferredLifetime 86400; 
 Base6to4Interface vlan2; 
 }; 
 }; 


in Adminstration > Commands, Startup Script:

 insmod /lib/modules/`uname -r`/ipv6.o
 sleep 5 
 radvd -C /tmp/radvd.conf start 
 sleep 5 
 WANIP=$(ip -4 addr show dev vlan2 | grep 'inet ' | awk '{print $2}' | cut -d/ -f1) 
 if [ -n "$WANIP" ] 
 then 
 V6PREFIX=$(printf '2002:%02x%02x:%02x%02x' $(echo $WANIP | tr . ' ')) 
 ip tunnel add tun6to4 mode sit ttl 255 remote any local $WANIP 
 ip link set tun6to4 mtu 1280 
 ip link set tun6to4 up 
 ip addr add $V6PREFIX:0::1/16 dev tun6to4 
 ip addr add $V6PREFIX:1::1/64 dev br0 
 ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 
 kill -HUP $(cat /var/run/radvd.pid) 
 fi 
 radvd -C /tmp/radvd.conf start

6to4 on k2.6 builds

The above scripts can be modified to use with 2.6 kernel builds, as follows:

Radvd config:

interface br0 { 
MinRtrAdvInterval 3; 
MaxRtrAdvInterval 10; 
AdvLinkMTU 1480; 
AdvSendAdvert on; 
prefix 0:0:0:1::/64 { 
AdvOnLink on; 
AdvAutonomous on; 
AdvValidLifetime 86400; 
AdvPreferredLifetime 86400; 
Base6to4Interface vlan2; 
}; 
}; 

Startup script:

insmod /lib/modules/`uname -r`/kernel/net/ipv6/sit.ko 
sleep 5 
radvd -C /tmp/radvd.conf start 
sleep 5 
WANIP=$(ip -4 addr show dev vlan2 | grep 'inet ' | awk '{print $2}' | cut -d/ -f1) 
if [ -n "$WANIP" ] 
then 
V6PREFIX=$(printf '2002:%02x%02x:%02x%02x' $(echo $WANIP | tr . ' ')) 
ip tunnel add tun6to4 mode sit ttl 255 remote any local $WANIP 
ip link set tun6to4 mtu 1480 
ip link set tun6to4 up 
ip addr add $V6PREFIX:0::1/16 dev tun6to4 
ip addr add $V6PREFIX:1::1/64 dev br0 
ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 
kill -HUP $(cat /var/run/radvd.pid) 
fi 
sleep 10 
radvd -C /tmp/radvd.conf start 

Note that this script is specifically for the WRT610N v1, where vlan2 is the WAN. On other routers, you may have to substitute vlan1.

Performance Concerns

When you send a packet from a 6to4 address to a native IPv6 address, it has to pass through a 6to4 gateway. RFC3068 established the special anycast address 192.88.99.1 which is supposed to lead you to the nearest gateway. However, some ISPs don't handle this properly, so you may find that all of your packets are crossing an ocean or two.

If this affects you, then you may need to do some detective work to locate a closer gateway. One possible approach is to use IPv4 Looking Glass tools to traceroute to 192.88.99.1 from various locations on the Internet and see where you end up.

Or you could bug your ISP about it, but they'll probably be like "IPvWHAT?"

6to4 IPv6 as default protocol

As per RFC3484 §2.1 default policy table, having a 6to4 enabled LAN (using a 6to4 anycast tunel on a DD-WRT enabled box, say) will mean that 6to4 IPv6 will only be used to communicate to a server if the server is having a 6to4 adress too (ie: 2002: prefix on its address) or if there is no IPv4 address assigned to the server name (ie: no A but an AAAA).

In short the following makes IPv4 default on IPv6 enabled Windows boxes using 6to4 prefixes.

1. Start -> Run -> "cmd" -> "netsh" -> "interface" -> "ipv6"

2. To enable IPv6 preference on Microsoft Windows...

set prefix ::1/128 50 0
set prefix ::/0 40 1
set prefix 2002::/16 30 1
set prefix ::/96 20 3
set prefix ::ffff:0/96 10 4
set prefix 2001::/32 5 5

Only the 2002::/16 line (6to4 prefix policy) is changed.

3. To make things goes back to original mode (IPv4 preference)...

set prefix ::1/128 50 0
set prefix ::/0 40 1
set prefix 2002::/16 30 2
set prefix ::/96 20 3
set prefix ::ffff:0/96 10 4
set prefix 2001::/32 5 5

And Voilà ;-)

Notes: ::1/128 == localhost, ::/0 == default, 2002::/16 == 6to4, ::/96 + ::ffff::0/96 == IPv4 compatibility, 2001::/32 == Teredo, 2000::/3 would be All IPv6 Global Unicast address space

SixXS Tunnel Broker

Requesting a Tunnel/Subnet

1. Sign up with a RIPE/ARIN/etc handle or by using the direct signup
2. After your login at the SixXS Home you can request a tunnel and later a subnet.

Note that providing a link to a XING or LinkedIn profile or providing links to projects you work on can provide extra credits!

Static Tunnel

There are instructions at Remoteroot.net with example scripts.

This wiki also offers an example IPv6 startup script

Notice that radvd doesn't work with mini version but requires the full version of DD-WRT. Also if you have problems with pinging and SixXS, notice their FAQ message related to this. By default DD-WRT seems to try to masquerade also the IPv6 packets so the following addition to the firewall rule worked for me:

 iptables -t nat -D POSTROUTING -o vlan2 -j MASQUERADE
 iptables -t nat -I POSTROUTING -p ! ipv6 -o vlan2 -j MASQUERADE

EDIT: You need to allow tunneled packets to be accepted on the interface! -deriamis

 iptables -I INPUT 2 -p ipv6 -i vlan2 -j ACCEPT

Dynamic Tunnel

Install AICCU

1. Install AICCU using ipkg.

 # ipkg -force-depends install http://downloads.openwrt.org/kamikaze/8.09.2/brcm47xx/packages/aiccu_20070115-2.1_mipsel.ipk

2. Configure AICCU.

 # vi /jffs/etc/aiccu.conf
 # AICCU Configuration
 
 # Login information
 username <your nichandle/username>
 password <your password>
 
 # Protocol and server listed on your tunnel
 protocol tic
 server tic.sixxs.net
 
 # Interface names to use
 ipv6_interface sixxs
 
 # The tunnel_id to use
 # (only required when there are multiple tunnels in the list)
 tunnel_id <your tunnel id>
 
 # Be verbose?
 verbose false
 
 # Daemonize?
 daemonize true
 
 # Require TLS?
 requiretls true
 
 # Set default route?
 defaultroute true

Note that if you can't write to /jffs/etc/, you can always store the script in another directory (that of course is persistent otherwise you loose it :) and use eg 'aiccu start /tmp/aiccu.conf' to pick a different configuration file location.

EDIT: A few other things are now necessary to make tunnels now... -deriamis

3. Install other required packages

 ipkg -force-depends install http://downloads.openwrt.org/kamikaze/8.09.2/brcm47xx/packages/kmod-ip6tables_2.6.25.20-brcm47xx-1_mipsel.ipk
 ipkg -force-depends install http://downloads.openwrt.org/kamikaze/8.09.2/brcm47xx/packages/ip6tables_1.4.0-1_mipsel.ipk

Automatically start your Tunnel

1. Put these lines into your startup script

insmod ipv6
insmod sit
insmod /jffs/lib/modules/2.6.25.20/ip6_tables.o 
insmod /jffs/lib/modules/2.6.25.20/ip6table_filter.o 
insmod /jffs/lib/modules/2.6.25.20/ip6t_multiport.o
sleep 5

WANIP=$(ip -4 addr show dev vlan2 | awk '/inet / {print $2}' | cut -d/ -f1) 
MY_TUNNEL_ADDR="<'Your IPv6' in tunnel info>"
TUNNEL_POP="<'PoP IPv6' in tunnel info>"
TUNNEL_REMOTE_IP="<'PoP IPv4' in tunnel info>"
echo "External IP:" $WANIP > /jffs/startup.debug
if [ -n $WANIP ]
then
echo "configuring tunnel" >> /jffs/startup.debug
fi

ip -6 tunnel add sixxs mode sit remote $TUNNEL_REMOTE_IP local $WANIP ttl 255
ip -6 link set sixxs up

# AICCU doesn't set up the tunnel properly but it will maintain the heartbeat for you
/usr/sbin/ntpclient -s -h us.pool.ntp.org
aiccu start /jffs/etc/config/aiccu

# Do all the things that AICCU was supposed to do and didn't
ip -6 addr add $MY_TUNNEL_ADDR/64 dev sixxs
ip -6 route add ::/0 dev sixxs

# WRONG ip -6 addr add $TUNNEL_POP dev sixxs
# WRONG  ip -6 addr add $TUNNEL_POP dev br0
ip route add 2000::/3 dev sixxs

# For each subnet you are routing, add one of these lines:
ip -6 addr add <Subnet Prefix without '::/48'>::1/64 dev br0

# Start IPv6 forwarding on the router
/bin/echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

2. Announce your Subnet with radvd

Enable radvd at the webinterface of your router (Administration->Management->IPv6 Support), then insert your radvd.conf into the form and save your settings.(You must use the /64 prefix even if you got a /48 subnet)

interface br0 { 
    AdvSendAdvert on; 
    AdvHomeAgentFlag on; 
    AdvLinkMTU 1480; 
    MinRtrAdvInterval 3; 
    MaxRtrAdvInterval 10; 
    prefix <Subnet Prefix without '::/48'>::/64 { 
        AdvOnLink on; 
        AdvAutonomous on; 
        AdvRouterAddr on; 
    }; 
};

3. Reboot the router!

When the router comes back up, you should be able to use IPv6. Congratulations!

Hurricane Electric's Tunnelbroker.net

Registration

1) Sign up for an account with our web based registration at Tunnelbroker.net

2) After creating your account, provide your IPv4 endpoint, and pick the closest tunnel-server to your location:

  • Fremont, CA
  • New York City, NY
  • Chicago, IL
  • Dallas, TX
  • London, UK
  • Frankfurt, DE
  • Paris, FR
  • Amsterdam, NL
  • Hong Kong, HK

Features

By default you already get a /64 allocation routed to your side of the tunnel.

If you need more than a single /64, with the click of a button you can allocate a single /48 routed to your side of the tunnel.

A large variety of configuration examples are provided for various platforms covering: Linux, *BSD, Windows as well as router platforms.

Tunnelbroker.net is operated and maintained by a business and not individuals, and provided FREE to anyone interested in learning more about IPv6.

Startup Script

This works for me on v24 SP2:

insmod ipv6
sleep 5
WANIP=$(ip -4 addr show dev vlan1 | awk '/inet / {print $2}' | cut -d/ -f1)
MY_TUNNEL_ADDR="2001:470:1f0e:5cd::2" # change me
MY_ROUTED_ADDR="2001:470:1f0f:5cd::1" # change me
echo "External IP:" $WANIP > /jffs/startup.debug
if [ -n $WANIP ]
then
echo "configuring tunnel" >> /jffs/startup.debug

# The following commands are straight from HE's website
ip tunnel add he-ipv6 mode sit remote 216.218.224.42 local $WANIP ttl 255
ip link set he-ipv6 up
ip addr add $MY_TUNNEL_ADDR/64 dev he-ipv6
ip route add ::/0 dev he-ipv6

# These commands aren't on HE's website, but they're necessary for the tunnel to work
ip -6 addr add $MY_ROUTED_ADDR/64 dev he-ipv6
ip -6 addr add $MY_ROUTED_ADDR/64 dev br0
ip route add 2000::/3 dev he-ipv6

echo "starting radvd" >> /jffs/startup.debug
radvd -C /jffs/radvd.conf &
fi
  • The tunnel address and routed address are on your Tunnel Details page on HE's website. For MY_TUNNEL_ADDR, use the value for "Client IPv6 Address", and for MY_ROUTER_ADDR, use the value for "Routed /64".
  • Many people have working configurations using only the tunnel address for everything, but you need to use the routed address for your network if you want certain things like reverse DNS to work.
  • You have to have your radvd config saved in /jffs/radvd.conf. Running radvd from the web interface has never worked for me; if it works for you, you can drop the radvd line from the script.
  • This script doesn't handle when your IP address changes; you'll need to manually update it on HE's website, or use the endpoint updater script below.
  • I occasionally have issues with the tunnel dying randomly. Pinging the router's IPv6 address fixes it for some reason, I have no idea why. :( -- update 2009.12.14 by calraith: Try adding metric 1 as an argument to the ip route add directives. ip route add ::/0 dev he-ipv6 metric 1
  • When you put your radvd config into the webgui (on administration tab) it is available at /tmp/radvd.conf. You can use this instead of creating a /jffs/radvd.conf file (I have issues with my jffs on my WRT350N). I have my startup.debug file in /tmp/startup.debug as well. ~methaneb

Endpoint updater

If your router gets a dynamic ip, you need to update your endpoint in your tunnelbroker account. This can be done on DDWRT with this busybox-only script: Tunnelbroker.net enpoint address updater

Download it into tmp or jffs, edit the file to set up your credentials or just run it from commandline:

updateipv4.sh username password tunnelid

A successful update means either your current endpoint IP is the same as your previous one, or it has been updated to your current one.

Additional Links

Tunnelbroker.net's user forums

IPv6 Setup with SAMBA

IPv6 Setup using NVRAM

Notes

Anonymous IPv6 at Microsoft Windows

By default on WinXP, Win2003 or WinVista, IPv6 addresses built from IPv6 prefix (stateless configuration for instance) are using the EUI-64 (cf MAC address) of your network card as a suffix. This can lead to some privacy issues, hence another IPv6 address is dynamically computed and used by default. Such an anonymous address changes (according to a computation algorithm) each time the IPv6 stack starts. This can cause some trouble under certain conditions where the server needs a unique and static IPv6 (containing the EUI-64). The solution is to deactivate the creation of those "privacy addresses". But be carefull, this will then lead to leaking the EUI-64 and also enables people to track you (logs, google, etc). So, it's a tradeoff.

If you want to disable temporary IPv6 addresses, try the command :

netsh interface ipv6 set privacy state=disable

or

ipv6 -p gpu UseTemporaryAddresses no

ping6 at dd-wrt v23

Try to install busybox from OpenWRT: http://downloads.openwrt.org/people/florian/bin/packages/

 ~ # ipkg install http://downloads.openwrt.org/people/florian/bin/packages/busybox_1.1.3-1_mipsel.ipk


Okay now you have to install uclibc (with -force-depends): http://downloads.openwrt.org/people/florian/bin/packages/

 ~ # ipkg -force-depends install http://downloads.openwrt.org/people/florian/bin/packages/uclibc_0.9.28-8_mipsel.ipk

After installing these packages you have to change the priority of the /lib path in your shell environment:

 ~ # export LD_LIBRARY_PATH=/usr/lib:/jffs/lib:/jffs/usr/lib:/jffs/usr/local/lib:/lib

For the last step you have to change the ping6 symlink:

 ~ # rm /jffs/bin/ping6
 ~ # cd /jffs/bin
 ~ # ln -s /jffs/bin/busybox ping6

Now ping6 should work for the current xterm session.

Troubleshooting

So you've tried to set up IPv6, but it didn't work! Don't panic, it's probably still fixable.

Tunnel issues

The first question to ask is, can you ping the router from the internet? Head over to [1] and use the ping test with your external IPv6 IP. (For HE and SixXS tunnels, this will be your client tunnel IP; for 6to4, it'll be generated from your public IPv4 address.) If the ping goes through, congratulations! Your tunnel isn't the problem.

6to4-specific issues

6to4 uses a special IP address (192.88.99.1) to configure the tunnel. Try pinging this IP; if it doesn't work, then 6to4 probably won't work for you. You could bother your ISP about it, but as likely as not they'll just ignore you completely.

6to4 also requires that protocol 41 (different from port 41!) be accessible. It's rare for ISPs to block this, but if they really feel like jerks it's not impossible. proto41 blocking is difficult to detect, unfortunately.

Hurricane Electric specific issues

Make sure your IPv4 address is set properly on the HE website. If not, your tunnel won't work. Similarly, make sure the IPv6 tunnel addresses you use are correct.

Radvd issues

If you're using radvd and it's not working somehow, then your router will have a working IPv6 connection, but it won't be passed on to your other computers. If your computers aren't receiving IPv6 addresses, then this is the problem.

The best tool for checking this is the radvdump program. Run it as root, and it'll show you any router advertisements your computer sends or receives. If you don't see any after a while, radvd probably isn't running. Try running "ps | grep radvd" on your router to see if it is. If it's not running, you can save your config file to jffs, and then run radvd manually:

radvd -C /jffs/radvd.conf

Beyond making sure IPv6 support is enabled on your client computers, you shouldn't have to configure anything else when using radvd.

Working configuration

For comparison, here's the output of a few commands on my router (which has a working HE.net tunnel):

root@DD-WRT:~# ip -6 addr show
1: lo: <LOOPBACK,MULTICAST,UP> 
    inet6 ::1/128 scope host 
3: eth0: <BROADCAST,MULTICAST,PROMISC,UP> 
    inet6 fe80::21c:10ff:fe5b:7978/64 scope link 
4: eth1: <BROADCAST,MULTICAST,PROMISC,UP> 
    inet6 fe80::21c:10ff:fe5b:797a/64 scope link 
5: vlan0: <BROADCAST,MULTICAST,PROMISC,UP> 
    inet6 fe80::21c:10ff:fe5b:7978/64 scope link 
6: vlan1: <BROADCAST,MULTICAST,UP> 
    inet6 fe80::21c:10ff:fe5b:7979/64 scope link 
7: br0: <BROADCAST,MULTICAST,UP> 
    inet6 2001:470:1f0f:5cd::1/64 scope global 
    inet6 fe80::21c:10ff:fe5b:7978/64 scope link 
10: he-ipv6: <POINTOPOINT,NOARP,UP> 
    inet6 2001:470:1f0f:5cd::1/64 scope global 
    inet6 2001:470:1f0e:5cd::2/64 scope global 
    inet6 fe80::48b3:3572/128 scope link
root@DD-WRT:~# ip -6 route show
2001:470:1f0e:5cd::/64 via :: dev he-ipv6  metric 256  mtu 1480 advmss 1420
2001:470:1f0f:5cd::/64 via :: dev he-ipv6  metric 256  mtu 1480 advmss 1420
2001:470:1f0f:5cd::/64 dev br0  metric 256  mtu 1500 advmss 1440
2000::/3 dev he-ipv6  metric 1024  mtu 1480 advmss 1420
fe80::/64 dev eth0  metric 256  mtu 1500 advmss 1440
fe80::/64 dev eth1  metric 256  mtu 1500 advmss 1440
fe80::/64 dev vlan0  metric 256  mtu 1500 advmss 1440
fe80::/64 dev vlan1  metric 256  mtu 1500 advmss 1440
fe80::/64 dev br0  metric 256  mtu 1500 advmss 1440
fe80::/64 via :: dev he-ipv6  metric 256  mtu 1480 advmss 1420
ff00::/8 dev eth0  metric 256  mtu 1500 advmss 1440
ff00::/8 dev eth1  metric 256  mtu 1500 advmss 1440
ff00::/8 dev vlan0  metric 256  mtu 1500 advmss 1440
ff00::/8 dev vlan1  metric 256  mtu 1500 advmss 1440
ff00::/8 dev br0  metric 256  mtu 1500 advmss 1440
ff00::/8 dev he-ipv6  metric 256  mtu 1480 advmss 1420
default dev he-ipv6  metric 1024  mtu 1480 advmss 1420

External Links