I think the newer kernel-5.5.7 issue is with xl2tpd, not the latest libreswan, try unblacklisting the L2TP kernel modules, see: https://github.com/nm-l2tp/NetworkManager-l2tp/wiki/Known-Issues#issue-with-blacklisting-of-l2tp-kernel-modules
The patch in this package (and the suggested Phase 1 Algorithm workaround for older versions of this package) is to avoid the following libreswan-3.30 config file syntax error:
ike string error: IKE DH algorithm 'modp1024' is not supported
L2TP/IPsec functionality is working, but now also need to issue the following to install the GUI component : dnf install NetworkManager-l2tp-gnome --enablerepo=updates-testing
Just to add bit of clarification. Previous versions didn't have a separate NetworkManager-l2tp-gnome RPM. I believe the intention of the Obsoletes added to NetworkManager-l2tp-gnome was so that it would get installed in an update.
Sorry I should have commented here earlier rather than sending an email directly to Lubomir (lkundrak).
I didn’t think the failed qa.depcheck for NetworkManager-l2tp 1.0.2-1fc23 involving the following line that was added later to the spec file I submitted:
Obsoletes: NetworkManager-l2tp < 1.2.2
would have let it get pushed through.
I guess the best option now is to change that line to either one of the following:
Obsoletes: NetworkManager-l2tp < 1.0
Obsoletes: NetworkManager-l2tp < 1.0.2