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-- 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/2055397 Title: netplan/systemd-networkd: route metric not applied to routes to the local subnet Status in cloud-init package in Ubuntu: Invalid Status in netplan.io package in Ubuntu: Invalid Status in systemd package in Ubuntu: Fix Released Status in systemd source package in Focal: Fix Committed Bug description: [SRU TEMPLATE] [DESCRIPTION] Cloud-init introduced a feature to configure policy routing on AWS EC2 instances with multiple NICs in https://github.com/canonical/cloud-init/commit/0ca5f31043e2d98eab31a43d9dde9bdaef1435cb targeting v24.1. Cloud-init generates the following netplan config: ``` $ cat /etc/netplan/50-cloud-init.yaml network: ethernets: ens5: dhcp4: true dhcp4-overrides: &id001 route-metric: 100 dhcp6: true dhcp6-overrides: *id001 match: macaddress: 0a:c8:ab:90:c2:fb set-name: ens5 ens6: dhcp4: true dhcp4-overrides: route-metric: 200 use-routes: true dhcp6: false match: macaddress: 0a:c6:55:a1:dc:3b routes: - table: 101 to: 0.0.0.0/0 via: 192.168.0.1 - table: 101 to: 192.168.0.0/20 routing-policy: - from: 192.168.10.212 table: 101 set-name: ens6 version: 2 ``` Which renders the following systemd-networkd config files: ``` $ cat 10-netplan-ens5.link [Match] MACAddress=0a:c8:ab:90:c2:fb [Link] Name=ens5 WakeOnLan=off $ cat 10-netplan-ens5.network [Match] MACAddress=0a:c8:ab:90:c2:fb Name=ens5 [Network] DHCP=yes LinkLocalAddressing=ipv6 [DHCP] RouteMetric=100 UseMTU=true $ cat 10-netplan-ens6.link [Match] MACAddress=0a:c6:55:a1:dc:3b [Link] Name=ens6 WakeOnLan=off $ cat 10-netplan-ens6.network [Match] MACAddress=0a:c6:55:a1:dc:3b Name=ens6 [Network] DHCP=ipv4 LinkLocalAddressing=ipv6 [Route] Destination=0.0.0.0/0 Gateway=192.168.0.1 Table=101 [Route] Destination=192.168.0.0/20 Scope=link Table=101 [RoutingPolicyRule] From=192.168.10.212 Table=101 [DHCP] RouteMetric=200 UseMTU=true ``` Which configures the instance with the following state in Ubuntu Focal: ``` $ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP group default qlen 1000 link/ether 0a:c8:ab:90:c2:fb brd ff:ff:ff:ff:ff:ff inet 192.168.12.94/20 brd 192.168.15.255 scope global dynamic ens5 valid_lft 2087sec preferred_lft 2087sec inet6 2a05:d012:ea0:c500:6d12:2b20:5fef:a502/128 scope global dynamic noprefixroute valid_lft 440sec preferred_lft 130sec inet6 fe80::8c8:abff:fe90:c2fb/64 scope link valid_lft forever preferred_lft forever 3: ens6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP group default qlen 1000 link/ether 0a:c6:55:a1:dc:3b brd ff:ff:ff:ff:ff:ff inet 192.168.10.212/20 brd 192.168.15.255 scope global dynamic ens6 valid_lft 2083sec preferred_lft 2083sec inet6 fe80::8c6:55ff:fea1:dc3b/64 scope link valid_lft forever preferred_lft forever $ ip route show default via 192.168.0.1 dev ens5 proto dhcp src 192.168.12.94 metric 100 default via 192.168.0.1 dev ens6 proto dhcp src 192.168.10.212 metric 200 192.168.0.0/20 dev ens5 proto kernel scope link src 192.168.12.94 192.168.0.0/20 dev ens6 proto kernel scope link src 192.168.10.212 192.168.0.1 dev ens5 proto dhcp scope link src 192.168.12.94 metric 100 192.168.0.1 dev ens6 proto dhcp scope link src 192.168.10.212 metric 200 $ ip rule show 0: from all lookup local 0: from 192.168.10.212 lookup 101 32766: from all lookup main 32767: from all lookup default $ ip route show table 101 default via 192.168.0.1 dev ens6 proto static onlink 192.168.0.0/20 dev ens6 proto static scope link ``` The issue here is that the instance is not reachable from the same subnet via the private ipv4 of the primary NIC, packets are routed to egress via ens6 and dropped. The cause is that interface metrics are not applied to local subnet routes with systemd 245 (245.4-4ubuntu3.23). On newer systemd versions, as in Jammy, the metrics are correctly applied. Correcting them manually fixes the issue in Focal. Expected main route table: default via 192.168.0.1 dev ens5 proto dhcp src 192.168.12.94 metric 100 default via 192.168.0.1 dev ens6 proto dhcp src 192.168.10.212 metric 200 192.168.0.0/20 dev ens5 proto kernel scope link src 192.168.12.94 metric 100 192.168.0.0/20 dev ens6 proto kernel scope link src 192.168.10.212 metric 200 192.168.0.1 dev ens5 proto dhcp scope link src 192.168.12.94 metric 100 192.168.0.1 dev ens6 proto dhcp scope link src 192.168.10.212 metric 200 It looks like the upstream systemd issue and PR fixing this problem are: https://github.com/systemd/systemd/issues/928 https://github.com/systemd/systemd/pull/19344 [TESTING] As described above. [REGRESSION POTENTIAL] The backport targets Focal. The fixing patches are touching network related code, regression potential would regard networking part of systemd, especially in address configuration. In particualar: * https://github.com/systemd/systemd/commit/aa550d2a51b025681ff8399e597338d35f540195 This patch adds sd_netlink_message_append_s* functions and types without modifying existing code. * https://github.com/systemd/systemd/commit/0e7bb99ff919bf8e6030ab7c3c178b87caf166a2 This one just adds missing address types * https://github.com/systemd/systemd/commit/c4ff0629dd450a40c5733b759eda08e6a032fae3 This one is adds the RouteMetric option for [Address]. Adds code to address_configure() function. * https://github.com/systemd/systemd/commit/415deef9c3e97211c862f39aceabf8e1f1485a41# This one adds the RouteMetric option to [DHCPv4] [OTHER] The upstream patches fixing this issue are the following : https://github.com/systemd/systemd/commit/aa550d2a51b025681ff8399e597338d35f540195 https://github.com/systemd/systemd/commit/0e7bb99ff919bf8e6030ab7c3c178b87caf166a2 https://github.com/systemd/systemd/commit/c4ff0629dd450a40c5733b759eda08e6a032fae3 https://github.com/systemd/systemd/commit/415deef9c3e97211c862f39aceabf8e1f1485a41 They originate in PR [1] and backported for focal in MR [2]. There's also a test package in [3]. [1] https://github.com/systemd/systemd/pull/19344 [2] https://code.launchpad.net/~joalif/ubuntu/+source/systemd/+git/systemd/+ref/lp2055397 [3] https://launchpad.net/~joalif/+archive/ubuntu/systemd-focal To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/2055397/+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
