** Description changed: + [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 + 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 + 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 + 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 - + 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
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2055397 Title: netplan/systemd-networkd: route metric not applied to routes to the local subnet To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/2055397/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
