Comment 14 for bug 2025519

There are 3 tests failing in Jammy: test_tunnel_gre6, test_tunnel_gre6_with_keys and test_tunnel_vti6.

networkd is logging some "Operation not supported" messages that appear to be related:

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Sep 08 16:45:53 jammy2 systemd-networkd[333]: tun0: netdev could not be created: Operation not supported
Sep 08 16:45:53 jammy2 systemd-networkd[333]: tun1: netdev could not be created: Operation not supported
Sep 08 16:45:53 jammy2 systemd-networkd[333]: tun2: netdev could not be created: Operation not supported
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Trying to create the ip6gre tunnel manually also fails, which means the kernel lacks support for it:

ip link add name tun0 type ip6gre local ::1 remote 1234:4321::1
Error: Unknown device type.

NetworkManager seems to be passing the GRE6 tests:

3204s test_tunnel_gre6 (__main__.TestNetworkManager) ... tun0 ok
3206s test_tunnel_gre6_with_keys (__main__.TestNetworkManager) ... tun0 ok

But if I try it manually on Jammy the interfaces will not be created and NM will log some errors:

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Sep 08 16:51:46 jammy2 NetworkManager[1550]: <info> [1694191906.6717] manager: (tun1): new IPTunnel device (/org/freedesktop/NetworkManager/Devices/3)
Sep 08 16:51:46 jammy2 NetworkManager[1550]: <warn> [1694191906.6727] platform-linux: do-add-link[tun1/ip6gre]: failure 95 (Operation not supported - Unknown device type)
Sep 08 16:51:46 jammy2 NetworkManager[1550]: <error> [1694191906.6728] manager: (netplan-tun1) couldn't create the device: Failed to create IPv6 tunnel interface 'tun1' for 'netplan-tun1': Operation not support>
Sep 08 16:51:46 jammy2 NetworkManager[1550]: <info> [1694191906.6730] manager: (tun0): new IPTunnel device (/org/freedesktop/NetworkManager/Devices/4)
Sep 08 16:51:46 jammy2 NetworkManager[1550]: <warn> [1694191906.6739] platform-linux: do-add-link[tun0/ip6gre]: failure 95 (Operation not supported - Unknown device type)
Sep 08 16:51:46 jammy2 NetworkManager[1550]: <error> [1694191906.6739] manager: (netplan-tun0) couldn't create the device: Failed to create IPv6 tunnel interface 'tun0' for 'netplan-tun0': Operation not support>
Sep 08 16:51:46 jammy2 NetworkManager[1550]: <info> [1694191906.6740] failed to open /run/network/ifstate
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Now, installing the linux-virtual-hwe-22.04 kernel (6.2) seems to resolve all these issues. All the tunnels tests pass and I can create the ip6gre manually, with networkd and with Network Manager.

That said, we should investigate why the NM tests are passing. Because it clearly can't create the gre6 interfaces.

To get this moving, we probably should disable these 3 tests as it's related to the default Jammy's kernel and we can verify they work fine with the new one.