Incoming IPv6 traffic works, outgoing IPv6 traffic does not

emansom · 2016-01-12 22:40:57

Recently I setup letsencrypt on my box and it kept timing out on a certificate request. Only falling back to IPv4 after an hour of timeouts. A bug report later and the issue was discovered: my box can't send outbound/outgoing IPv6 traffic.

This is probably caused by a misconfiguration from my end. The wiki seems vague on how to setup both static IPv4 and IPv6 using systemd-networkd. How can I resolve this issue?

Here is my current systemd-networkd configuration:

/etc/systemd/network/ens3.network

[Match]
Name=ens3

[Network]
DNS=2a01:7c8:b::c53
DNS=2a01:7c8:a::c53
Address=2a01:7c8:aab9:573::1/48
Gateway=2a01:7c8:aab9::1

DNS=80.69.66.67
DNS=80.69.67.66
Address=149.210.217.208/24
Gateway=149.210.217.1

DNS=2a01:7c8:b::c53
DNS=2a01:7c8:a::c53
Address=2a01:7c8:aab9:573::2/48
Gateway=2a01:7c8:aab9::1

DNS=2a01:7c8:b::c53
DNS=2a01:7c8:a::c53
Address=2a01:7c8:aab9:573::3/48
Gateway=2a01:7c8:aab9::1

DNS=80.69.66.67
DNS=80.69.67.66
Address=149.210.218.102/24
Gateway=149.210.218.1

systemd-networkd is also spamming the journal full with these messages:

Could not remove route: Invalid argument
Could not send rtnetlink message: Invalid argument

Last edited by emansom (2016-01-12 23:27:20)

fukawi2 · 2016-01-13 00:01:35

What is the output of `ip -6 addr show` and `ip -6 route show`? Can you `ping6 2a01:7c8:aab9::1`?

Last edited by fukawi2 (2016-01-13 00:01:50)

emansom · 2016-01-13 00:07:59

fukawi2 wrote:

What is the output of `ip -6 addr show` and `ip -6 route show`? Can you `ping6 2a01:7c8:aab9::1`?

`ip -6 addr show`

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN 
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 2a01:7c8:aab9:0:5054:ff:feb5:e8dd/48 scope global noprefixroute dynamic 
       valid_lft 2591599sec preferred_lft 604399sec
    inet6 2a01:7c8:aab9:573::3/48 scope global 
       valid_lft forever preferred_lft forever
    inet6 2a01:7c8:aab9:573::2/48 scope global 
       valid_lft forever preferred_lft forever
    inet6 2a01:7c8:aab9:573::1/48 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:feb5:e8dd/64 scope link 
       valid_lft forever preferred_lft forever

`ip -6 route show`

2a01:7c8:aab9::/48 dev ens3  proto kernel  metric 256  pref medium
2a01:7c8:aab9::/48 dev ens3  proto ra  metric 1024  pref medium
fe80::/64 dev ens3  proto kernel  metric 256  pref medium
default via 2a01:7c8:aab9::1 dev ens3  proto static  metric 1024  pref medium
default via fe80::fab1:56ff:fe6a:59e5 dev ens3  proto ra  metric 1024  pref medium
default via fe80::aab9:1 dev ens3  proto ra  metric 1024  pref medium
default via fe80::fab1:56ff:fe65:b0bc dev ens3  proto ra  metric 1024  pref medium

`ping6 2a01:7c8:aab9::1`

PING 2a01:7c8:aab9::1(2a01:7c8:aab9::1) 56 data bytes
^C
--- 2a01:7c8:aab9::1 ping statistics ---
206 packets transmitted, 0 received, 100% packet loss, time 204999ms

Last edited by emansom (2016-01-13 00:10:23)

fukawi2 · 2016-01-13 02:56:37

default via 2a01:7c8:aab9::1 dev ens3  proto static  metric 1024  pref medium
default via fe80::fab1:56ff:fe6a:59e5 dev ens3  proto ra  metric 1024  pref medium
default via fe80::aab9:1 dev ens3  proto ra  metric 1024  pref medium
default via fe80::fab1:56ff:fe65:b0bc dev ens3  proto ra  metric 1024  pref medium

So um, how have you ended up with 4 different default gateways? Three look like they have come from RA's, so you have 3 different devices announcing RA's on your network which is probably not right. The ping may not mean anything (I can't get a ping response from it either, so may be blocking ICMP echos)

branch · 2016-01-14 16:56:45

Why are you specifying the same DNS servers and the same gateway three times in your .network file?
Why are you configuring 3 addresses on the same subnet?
Are you really on the same subnet as the gateway you are setting (is it really an un-partitioned /48)?

Simplify your configuration. Then, since you said you want static configuration, set IPv6AcceptRouterAdvertisements=false in your .network file and reboot. If you are still having problems here are some commands that might give you more insight:

See if the gateway you set is really on-link:

ndisc6 2a01:7c8:aab9::1 ens3

See if the default route is what you expect:

ip -6 route get 1234::0

Arch Linux

#1 2016-01-12 22:40:57

Incoming IPv6 traffic works, outgoing IPv6 traffic does not

#2 2016-01-13 00:01:35

Re: Incoming IPv6 traffic works, outgoing IPv6 traffic does not

#3 2016-01-13 00:07:59

Re: Incoming IPv6 traffic works, outgoing IPv6 traffic does not

#4 2016-01-13 02:56:37

Re: Incoming IPv6 traffic works, outgoing IPv6 traffic does not

#5 2016-01-14 16:56:45

Re: Incoming IPv6 traffic works, outgoing IPv6 traffic does not

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