** Description changed: The following code in DeviceManager's fill_dhcp_udp_checksums assumes IPv6 is always enabled: iptables_mgr = iptables_manager.IptablesManager(use_ipv6=True, namespace=namespace) When iptables_mgr.apply() is later called, an attempt to add the UDP checksum rule for DHCP is done via iptables-save/iptables-restore and if IPv6 has been disabled on a hypervisor (eg, by setting `ipv6.disable=1` on the kernel command line) then an many-line error occurs in the DHCP agent logfile. There should be a way of telling the agent that IPv6 is disabled and as such, it should ignore trying to set up the UDP checksum rule for IPv6. This can be easily achieved given that IptablesManager already has support for disabling it. We've seen this on Rocky on Ubuntu Bionic but it appears the issue still exists on the master branch. ================================= Ubuntu SRU details: - [Impact] - See above. + + [Impact] - [Test Case] - Deploy openstack on a hypervisor with IPv6 disabled. - Create a network which has a subnetwork with DHCP enabled. - Search the `neutron-dhcp-agent.log` (with debug log enabled) and check if there are any `ip6tables-restore` commands. + See above - [Regression Potential] - Minimal. - Users which were relying on the setting to always be true could be affected. + + [Test Plan] + + Disable IPv6 on a hypervisor. + sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1 + sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1 + sudo sysctl -w net.ipv6.conf.lo.disable_ipv6=1 + Deploy Openstack Ussuri or Victoria with one compute node, using the hypervisor which has IPv6 disabled as a neutron gateway. + Create a network which has a subnetwork with DHCP enabled. Eg: + openstack network create net1 + openstack subnet create subnet1 --network net1 --subnet-range 192.0.2.0/24 --dhcp + Search the `/var/log/neutron/neutron-dhcp-agent.log` (with debug log enabled) and check if there are any `ip6tables-restore` commands. Eg: + sudo grep ip6tables-restore /var/log/neutron/neutron-dhcp-agent.log + + [Where problems could occur] + + Users which were relying on the setting to always be true could be + affected.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1915480 Title: DeviceManager's fill_dhcp_udp_checksums assumes IPv6 available To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-archive/+bug/1915480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
