Hi, this bug is affecting me as well on Focal (Ubuntu 20.04). I used the option use-routes=false in netplan to ignore the default gateway and now it doesn't work. As you have explained, now the right way is to use the UseGateway option of systemd.
But there is no option in the current version of netplan. Netplan says "unknown key 'use-gateway'" Also, there is no option in the current version of systemd. Systemd says "Unknown key name 'UseGateway' in section 'DHCP', ignoring." Is there any workaround, because now I'm stuck and don't know how to accomplish this? Also is it planned to be included with simple updates or only in a future "Ubuntu 20.10" release? -- 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: In Progress Status in netplan.io source package in Bionic: Invalid Status in systemd source package in Bionic: In Progress Status in netplan.io source package in Eoan: Invalid Status in systemd source package in Eoan: In Progress Status in netplan.io source package in Focal: New Status in systemd source package in Focal: In Progress Status in netplan.io source package in Groovy: New Status in systemd source package in Groovy: In Progress 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. [scope] This is fixed by these upstream PRs: https://github.com/systemd/systemd/pull/15443 https://github.com/systemd/systemd/pull/15136 https://github.com/systemd/systemd/pull/14983 Parts of all those PRs are required in Focal, Eoan, and Bionic. I am not fixing this for Xenial, at this time. For Debian, I opened this MR: https://salsa.debian.org/systemd-team/systemd/-/merge_requests/92 For Groovy, I opened this MR: https://code.launchpad.net/~ddstreet/ubuntu/+source/systemd/+git/systemd/+merge/383661 [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
