Note for netplan.io: if the PR is accepted, then there shouldn't be any need for immediate change in netplan; however in the future, netplan likely will need a new option 'use-gateway', similar to the existing 'use-routes' parameter.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1867375 Title: systemd-networkd: UseRoutes behavior change with introduction of UseGateway param Status in netplan.io package in Ubuntu: New Status in systemd package in Ubuntu: Fix Released Status in netplan.io source package in Bionic: Invalid Status in systemd source package in Bionic: Confirmed Status in netplan.io source package in Eoan: Invalid Status in systemd source package in Eoan: Confirmed Status in netplan.io source package in Focal: New Status in systemd source package in Focal: Fix Released Bug description: [impact] the networkd UseRoutes parameter allowed ignoring all routes provided by a dhcp4 server, including the route via the dhcp4-provided gateway. This was the behavior of networkd until recently, and in Focal the UseRoutes parameter does *not* prevent networkd from adding the route via the dhcp4-provided gateway. This is now controlled with a new parameter, UseGateway. The systemd in Focal unfortunately has part of the upstream code; it no longer ignores the gateway route when UseRoutes=false is specified, but also it does not include the UseGateway parameter. Before Focal, networkd did not allow ignoring dhcpv4 routes and the gateway separately; the UseRoutes= parameter either used, or ignored, both. This is why upstream added the UseGateway= paramter, which should be backported to allow control of ignoring the dhcpv4 routes and gateway separately. [test case] In Focal, bug 1872589 has a good test case netplan config, but a very quick test can be done with the networkd config: [Match] Name=eth0 [Network] DHCP=ipv4 LinkLocalAddressing=ipv6 [DHCP] RouteMetric=100 UseMTU=true UseRoutes=false this results in the system incorrectly setting a route via the default gateway: root@lp1867375-f:~# ip r default via 10.202.51.1 dev eth0 proto dhcp src 10.202.51.86 metric 100 10.202.51.0/24 dev eth0 proto kernel scope link src 10.202.51.86 10.202.51.1 dev eth0 proto dhcp scope link src 10.202.51.86 metric 100 Before Focal, the above test case shows "correct" behavior, but there is no way to ignore the dhcpv4 routes but use the dhcpv4 gateway. This pre-Focal, the test case would be to use the UseGateway= parameter, e.g.: [Match] Name=eth0 [Network] DHCP=ipv4 LinkLocalAddressing=ipv6 [DHCP] RouteMetric=100 UseMTU=true UseRoutes=false UseGateway=true which *should* result in the default gateway being configured: root@lp1867375-f:~# ip r default via 10.202.51.1 dev eth0 proto dhcp src 10.202.51.86 metric 100 10.202.51.0/24 dev eth0 proto kernel scope link src 10.202.51.86 10.202.51.1 dev eth0 proto dhcp scope link src 10.202.51.86 metric 100 [regression potential] Any regression would likely involve incorrect setting, or ignoring, of dhcpv4-provided routes, and/or incorrect setting, or ignoring, of the dhcpv4-provided gateway. [other info] to properly support separation of 'routes' and 'gateways' received via dhcp4, SRU releases should also support the UseGateway parameter, which is what this bug was originally opened requesting. [original description] requesting backport of PR https://github.com/systemd/systemd/pull/14983 which fixes the issue described in https://github.com/systemd/systemd/issues/14982 to 18.04 (bionic) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/netplan.io/+bug/1867375/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
