# Ipv6 not working

**URL:** <https://forums.docker.com/t/ipv6-not-working/10171>\
**Category:** General\
**Created:** [April 26, 2016, 7:10pm UTC](https://forums.docker.com/t/ipv6-not-working/10171 "2016-04-26T19:10:46Z")\
**Posts on this page:** 1\
**Showing post:** 7

<div class="post-metadata">

**Author:** ![schinzelh](https://sea3.discourse-cdn.com/docker/user_avatar/forums.docker.com/schinzelh/32/9656_2.png) [@schinzelh](https://forums.docker.com/u/schinzelh)\
**Post date:** [May 9, 2016, 1:47pm UTC](https://forums.docker.com/t/ipv6-not-working/10171/7 "2016-05-09T13:47:50Z")

</div>

I ran into a similar problem, maybe it is of help:

My host has a public routable /64 ipv6 subnet assigned. I’ve added

```auto
DOCKER_OPTS="--dns 8.8.8.8 --dns 8.8.4.4 --fixed-cidr-v6=2607:5300:60:a7bc:2::/80 --ipv6"

```

to my docker deamon settings to assign a /80 subnet to Docker. The docker container ended up with

```auto
eth0 Link encap:Ethernet HWaddr 02:42:ac:11:00:03
          inet addr:172.17.0.3 Bcast:0.0.0.0 Mask:255.255.0.0
          inet6 addr: 2607:5300:60:a7bc:2:242:ac11:3/80 Scope:Global
          inet6 addr: fe80::42:acff:fe11:3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:7 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:738 (738.0 B) TX bytes:508 (508.0 B)

```

with `2607:5300:60:a7bc:2:242:ac11:3` being pingable from host machine, but the container not being able to reach outside world. I finally gave the [NDP proxy](https://docs.docker.com/engine/userguide/networking/default_network/ipv6/#using-ndp-proxying) you mentioned above a try, and it did the trick for me:

```auto
$ sysctl net.ipv6.conf.eth0.proxy_ndp=1

```

and

```auto
$ ip -6 neigh add proxy 2607:5300:60:a7bc:2:242:ac11:3 dev eth0

```

Hope that helps,  
Holger

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