(Maybe) Multiple Network Rendering Bugs

These are my subjective judgments. They might bugs, or not. Not tested. Developers can close this thread at any time. --- ### 1 https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/network_state.py#L406 If this line also applies to network config v1. The v1 types `ipv6_dhcpv6-stateful`, `ipv6_dhcpv6-stateless`, and `ipv6_slaac` results `false` here Obviously, it is handled well here: https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/__init__.py#L1301 ### 2 As far as I know, in the Subnet type of network configuration, `dhcp6` is equivalent to `ipv6_dhcpv6-stateful`. However, in the following places, `dhcp6` and `ipv6_dhcpv6-stateful` are treated differently, resulting in different outcomes: https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/network_manager.py#L137-L146 https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/network_manager.py#L167-L171 https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/networkd.py#L211 https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/sysconfig.py#L439 The last one I previously reported https://github.com/canonical/cloud-init/issues/4615 There might be similar issues elsewhere. ### 3 https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/eni.py#L577-L581 Similar issues. `dhcp` is equivalent to `dhcp4`. Should add `dhcp` here ### 4 https://github.com/canonical/cloud-init/blob/d7eb828f8e232a1ce6d2fa66f8028a3b10adab1f/cloudinit/net/sysconfig.py#L1119-L1121 `IPV6_AUTOCONF=no` is set here. It should be enabled by default.