{"id":4084,"date":"2021-02-08T10:00:00","date_gmt":"2021-02-08T16:00:00","guid":{"rendered":"https:\/\/www.foell.org\/justin\/?p=4084"},"modified":"2021-02-07T15:53:29","modified_gmt":"2021-02-07T21:53:29","slug":"openwrt-bridging-with-ipv6-support","status":"publish","type":"post","link":"https:\/\/www.foell.org\/justin\/openwrt-bridging-with-ipv6-support\/","title":{"rendered":"OpenWrt Bridging with IPv6 support"},"content":{"rendered":"\n

My network topology at home is pretty simple, it looks like this:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

After my recent router hardware and OpenWrt 19.07 firmware upgrades<\/a>, I noticed my access point connected to my cable modem looked like this on the Status Overview page:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

Pro-tip: Notice I’m using the cloudflare DNS servers<\/a> rather than the ISP-provided ones. The Comcast DNS servers have gone down on me before and their performance is generally lacking.<\/p><\/blockquote>\n\n\n\n\n\n\n\n

But over on my bridged router it looked like this:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

Further more, when I went to the command line on my bridged router, I couldn’t ping any IPv6 addresses:<\/p>\n\n\n\n

root@ap2:~# ping ipv6.google.com\nPING ipv6.google.com (2607:f8b0:4009:807::200e): 56 data bytes\nping: sendto: Permission denied<\/code><\/pre>\n\n\n\n
My concern was if the bridged router can’t contact IPv6 addresses, the same is probably true for the devices that are connecting through it.<\/p>\n\n\n\n
I found the solution in this thread on the OpenWrt forums.<\/a> While it’s easy to statically assign an IPv4 address, along with a default gateway and DNS server – for IPv6 it’s easiest to set up another lan interface specifically for IPv6 that gets it’s IPv6 address (and routes) automatically from the upstream router – rather than assigning it statically.<\/p>\n\n\n\n
The TL;DR version of this post is to add this to your network config:<\/p>\n\n\n\n
config interface 'lan6'\n\toption ifname '@lan'\n\toption proto 'dhcpv6'\n\toption reqprefix 'no'<\/code><\/pre>\n\n\n\n
Configuring IPv6 Bridging through the Web Interface<\/h2>\n\n\n\n
To do the same thing above via LuCI – the OpenWrt web interface, here’s how. Initially on the Network -> Interfaces page, ou can see my IPv4 lan with the wan ports disabled:<\/p>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
Click “Add new interface…”<\/p>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
Name it “lan6” and choose the DHCPv6 client protocol. For the interface, select the @lan alias. Then click Create Interface. You’ll be brought to a second screen.<\/p>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
All I had to do on this page was change the “Request IPv6-prefix” value to disabled. No need to change anything on the other tabs – the defaults are fine.<\/p>\n\n\n\n
Now the Status -> Overview page on my bridged router looks like this:<\/p>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
Now I can ping IPv6 addresses from the command line on my bridged router:<\/p>\n\n\n\n
root@ap2:~# ping -c 2 ipv6.google.com\nPING ipv6.google.com (2607:f8b0:4009:807::200e): 56 data bytes\n64 bytes from 2607:f8b0:4009:807::200e: seq=0 ttl=115 time=17.884 ms\n64 bytes from 2607:f8b0:4009:807::200e: seq=1 ttl=115 time=17.351 ms\n\n--- ipv6.google.com ping statistics ---\n2 packets transmitted, 2 packets received, 0% packet loss\nround-trip min\/avg\/max = 17.351\/17.617\/17.884 ms<\/code><\/pre>\n\n\n\n
One of my 2021 goals is to better understand IPv6 concepts (at least as well as I can understand IPv4). If there’s any *nix configurations I find helpful along the way, I’ll post ’em here.<\/p>\n
Send to Kindle<\/span><\/div>","protected":false},"excerpt":{"rendered":"
My network topology at home is pretty simple, it looks like this: After my recent router hardware and OpenWrt 19.07 firmware upgrades, I noticed my access point connected to my cable modem looked like this on the Status Overview page: Pro-tip: Notice I’m using the cloudflare DNS servers rather than the ISP-provided ones. The Comcast… Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1,8],"tags":[178,24],"class_list":["post-4084","post","type-post","status-publish","format-standard","hentry","category-business","category-ubuntu","tag-ipv6","tag-openwrt"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t