Cannot add wg0 on CentOS 8

[Toke Høiland-Jørgensen]

Phil Perry <pperry at elrepo.org> writes:

> On 09/12/2021 10:47, Mehdi Haghgoo wrote:
>> Hi,
>> 
>> I'm trying to add  a wireguard device on CentOS Stream (was Linux just converted to Stream).
>> When I enter "ip link add wg0 type wireguard" or try it using wg-quick wg0 up, I get the following error:
>> 
>> RTNETLINK answers: Operation not supported
>> 
>> I have wireguard-tools and kmod-wireguard installed.
>> Additional information:
>> 
>> uname -r: 4.18.0-147.8.1.el8_1.x86_64
>> 
>> wg --version: wireguard-tools v1.0.20210914 - https://git.zx2c4.com/wireguard-tools/
>> 
>> kmod-wireguard version: 1.0.20211208
>> 
>> 
>> Best regards,
>> Mehdi
>
> Is the wireguard module loaded? I doubt it.
>
> You are running a *very* old kernel, and I suspect the version of 
> kmod-wireguard you are running does not support that kernel. Why are you 
> running a kernel that is two years out of date and full of unpatched 
> security holes?

RHEL (and thus CentOS) kernel version numbers are a complete fiction, so
don't mind the '4.18'. The important bit is the '-147' at the end, which
is still way out of date, though...

> Updating your system is probably the first step to fixing your issue.

My guess would be that he actually did update the system, it's just
running the old kernel still? I.e., if you install kmod-wireguard from
elrepo, that depends on a specific version of the kernel (-348 in the
current version), but if you haven't rebooted to actually run that
kernel, the module is obviously not going to work...

So, erm, Mehdi, have you tried turning it off and back on again? ;)

-Toke