Arch Linux

AtmIgn

Member

Registered: 2024-12-18

Posts: 13

Obtaining IPv6 address on a VPS

I'm using Arch Linux on my VPS, which supports both IPv4 and IPv6.

Setting an IPv4 DNS record and connectivity was easy enough, but my VPS seems to have no IPv6 address.

$ ip -6 addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host noprefixroute
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 fe80::33f7:c8bb:1766:5790/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

On the VPS control panel, the IPv6 section looks something like (actual address redacted):

fe80::58ba:66ff:fea8:26e8/10
xxxx:xxxx:xxxx:xxxx::/64

As far as my understanding of the Arch Wiki and other internet searches, there is something I need to do on my VPS in order for the OS to obtain and announce an address from the /64 IPv6 subnet allocated to me, and the Link-Local Unicast address (fe80::58ba:66ff:fea8:26e8/10) is somehow related to that, but I'm completely lost as to how I would go about that.

As a sanity check, I tried installing Debian to a different VPS from that same provider, and IPv6 was working out of the box, so I'm pretty sure the issue is with my configuration.

Thank you for help or advice.

-thc

Member

Registered: 2017-03-15

Posts: 928

Re: Obtaining IPv6 address on a VPS

I tried installing Debian to a different VPS from that same provider, and IPv6 was working out of the box, so I'm pretty sure the issue is with my configuration.

That hints to successfully obtaining an IPv6 address automatically (DHCPv6, SLAAC).

How do you manage the network configuration of your VPS?

AtmIgn

Member

Registered: 2024-12-18

Posts: 13

Re: Obtaining IPv6 address on a VPS

I haven't really done anything other than enabling NetworkManager, and setting up systemd-resolved.

-thc

Member

Registered: 2017-03-15

Posts: 928

Re: Obtaining IPv6 address on a VPS

That's strange - NetworkManager on it's defaults should also acquire an IPv6 address automatically (like Debian's setup routine).

Can you show us what NetworkManager does:

journalctl -b | grep NetworkManager

ugjka

Member

From: Latvia

Registered: 2014-04-01

Posts: 1,920

Website

Re: Obtaining IPv6 address on a VPS

which vps provider is this and is this their official archlinux image? I'm asking this because vps providers in their images add scripts that set everything up for you

Last edited by ugjka (2025-06-14 13:26:54)

---

https://ugjka.net

cryptearth

Member

Registered: 2024-02-03

Posts: 1,527

Re: Obtaining IPv6 address on a VPS

you could look into the config of the debian system how ipv6 is setup there and copy it to the arch one with just replcing the correct ip
I did exactly that on my new OVH root as I wasn't able to figure it out myself
in case of OVH: https://bbs.archlinux.org/viewtopic.php … 8#p2226528

AtmIgn

Member

Registered: 2024-12-18

Posts: 13

Re: Obtaining IPv6 address on a VPS

Thanks for the pointers. I created a file under

/etc/systemd/network/20-wired.network

containing

[Match]
Name=ens3

[Link]
RequiredForOnline=routable

[Network]
# IPv4 configuration
Address=152.53.aa.bb/22
Gateway=152.53.83.255

# IPv6 configuration
Address=aaaa:bbbb:cccc:dddd::/64
Gateway=aaaa:bbbb:cccc:dddd::1

Running ip -6 commands now shows the addresses I configured for systemd-networkd, but running ping -6 archlinux.org shows "Destination unreachable: Address unreachable" errors, instead of immediately failing with "Network Unreachable". I guess I managed to turn on IPv6 for the interface, but configured something wrong.

$ ip -6 addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host noprefixroute
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 aaaa:bbbb:cccc:dddd::/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::58ba:66ff:fea8:26e8/64 scope link proto kernel_ll
       valid_lft forever preferred_lft forever
    inet6 fe80::33f7:c8bb:1766:5790/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

$ ip -6 route show
aaaa:bbbb:cccc:dddd::/64 dev ens3 proto kernel metric 256 pref medium
fe80::/64 dev ens3 proto kernel metric 256 pref medium
fe80::/64 dev ens3 proto kernel metric 1024 pref medium
default via aaaa:bbbb:cccc:dddd::1 dev ens3 proto static metric 1024 pref medium

$ ip -6 neigh show
aaaa:bbbb:cccc:dddd::1 dev ens3 FAILED
fe80::66c3:d607:defe:3943 dev ens3 FAILED

EDIT: I didn't use my provider's Arch Linux image, I made my own QCOW image inside a VM on my home machine.

Last edited by AtmIgn (2025-06-14 15:16:42)

-thc

Member

Registered: 2017-03-15

Posts: 928

Re: Obtaining IPv6 address on a VPS

So basically ignoring Debian's "magic" and a non-installed "NetworkManager" the most probable solution - if this is a netcup vServer, which the IPv4 addresses suggest - IMHO would be something like this:

[Match]
Name=ens3

[Link]
RequiredForOnline=routable

[Network]
# IPv4 configuration
Address=152.53.aa.bb/22
Gateway=152.53.83.255

# IPv6 configuration
Address=aaaa:bbbb:cccc:dddd::1/64
Gateway=fe80::1

AtmIgn

Member

Registered: 2024-12-18

Posts: 13

Re: Obtaining IPv6 address on a VPS

Sorry for the late reply. I tried to enter the values you suggested into /etc/systemd/network/20-wired.network, but after double-checking the IP addresses to be correct, and that NetworkManager and systemd-networkd and both running, I completely loose all IPv4 and IPv6 connectivity on the server, including SSH access. I needed to VNC back into the server to revert my changes.

-thc

Member

Registered: 2017-03-15

Posts: 928

Re: Obtaining IPv6 address on a VPS

[...]and that NetworkManager and systemd-networkd and both running, I completely loose all IPv4 and IPv6 connectivity on the server, including SSH access.

What? Don't use concurrent network managements. Choose one.