The difference between bridges managing to come up correctly and the ones which does not seem to be that bridges defined as "inet manual" fails and the ones defined as "inet static" succeeds. An example of a bridge coming up correctly with a similar setup without the post-up brctl addbr command;
auto int0.70 iface int0.70 inet manual vlan-raw-device int0 pre-up ifconfig $IFACE up post-down ifconfig $IFACE down auto br_nat iface br_nat inet static bridge_ports int0.70 bridge_maxwait 5 address 172.X.X.X/24 up ip ro add 10.X.X.X/10 via 172.X.X.X dev $IFACE So two conclusions; 1) Bridges configured with bridge_ports with interfaces defined as "inet manual" while the bridge is also configured as "inet manual" will fail to come up correctly. 2) If a bridge fails to come up with the inet manual directive the dhclient for br_ext_prim also dies after receiving one lease. Reservation on #1 that this could probably also be true with an "inet static" interface for a bridge configured as "inet manual". Both of the above works 100% fine in 18.04. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1874515 Title: 20.04 does not bring up certain bridges Status in ifupdown package in Ubuntu: New Bug description: After upgrading from a fully patched ubuntu-server 18.04 to 20.04 and rebooting I noticed that some of my bridge interfaces defined in /etc/network/interfaces would not come up while others would. Bridges brought up at boot: br_ext_prim br_ext_sec br_int_50 br_nat Bridges missing: br_int_500 br_nat_ext Relevant log from 18.04 prior to upgrade: Apr 23 19:11:37 fancy systemd-udevd[725]: Could not generate persistent MAC address for br_nat_ext: No such file or directory Apr 23 19:11:37 fancy systemd[1]: Found device /sys/subsystem/net/devices/br_nat_ext. Apr 23 19:11:37 fancy systemd[1]: Started ifup for br_nat_ext. Apr 23 19:11:37 fancy systemd-networkd[2284]: br_nat_ext: Link UP Apr 23 19:11:37 fancy sh[2383]: Waiting for br_nat_ext to get ready (MAXWAIT is 5 seconds). Apr 23 19:11:37 fancy kernel: [ 9.447538] br_nat_ext: port 1(int0.51) entered blocking state Apr 23 19:11:37 fancy kernel: [ 9.447540] br_nat_ext: port 1(int0.51) entered disabled state Apr 23 19:11:37 fancy systemd-networkd[2284]: br_nat_ext: Gained carrier Apr 23 19:11:37 fancy kernel: [ 10.942682] br_nat_ext: port 1(int0.51) entered blocking state Apr 23 19:11:37 fancy kernel: [ 10.942683] br_nat_ext: port 1(int0.51) entered forwarding state Apr 23 19:11:37 fancy kernel: [ 10.943270] IPv6: ADDRCONF(NETDEV_CHANGE): br_nat_ext: link becomes ready Apr 23 19:11:39 fancy systemd-networkd[2284]: br_nat_ext: Gained IPv6LL Relevant log from 20.04 after upgrade: Apr 23 19:39:52 fancy ifup[1845]: br_nat_ext: ERROR while getting interface flags: No such device Apr 23 19:39:52 fancy ifup[1066]: ifup: failed to bring up br_nat_ext Apr 23 19:40:04 fancy libvirtd[1935]: Cannot get interface MTU on 'br_nat_ext': No such device Apr 23 19:40:04 fancy libvirtd[1935]: internal error: Failed to autostart VM 'dns': Cannot get interface MTU on 'br_nat_ext': No such device Apr 23 19:43:43 fancy libvirtd[1935]: Cannot get interface MTU on 'br_nat_ext': No such device Apr 23 19:39:52 fancy systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE Apr 23 19:39:52 fancy systemd[1]: networking.service: Failed with result 'exit-code'. Apr 23 19:39:52 fancy systemd[1]: Failed to start Raise network interfaces. Similar logs show up for br_int_500. Some examples of entries of /etc/network/interfaces: Not working: # NAT via main FW auto int0.51 iface int0.51 inet manual vlan-raw-device int0 pre-up ifconfig $IFACE up post-down ifconfig $IFACE down auto br_nat_ext iface br_nat_ext inet manual bridge_ports int0.51 bridge_maxwait 5 pre-up ifconfig $IFACE up post-down ifconfig $IFACE down Working: # 1GE auto ext0.10 iface ext0.10 inet manual vlan-raw-device ext0 pre-up ifconfig $IFACE up post-down ifconfig $IFACE down # Secondary bridge 1GE auto br_ext_sec iface br_ext_sec inet manual bridge_ports ext0.10 bridge_maxwait 5 post-up ifconfig $IFACE up post-down ifconfig $IFACE down Output from syslog in regards to br_ext_sec after upgrade: Apr 23 19:39:52 fancy systemd-udevd[1366]: br_ext_sec: Could not generate persistent MAC: No data available Apr 23 19:39:52 fancy kernel: [ 24.353151] br_ext_sec: port 1(ext0.10) entered blocking state Apr 23 19:39:52 fancy kernel: [ 24.353156] br_ext_sec: port 1(ext0.10) entered disabled state Apr 23 19:39:52 fancy systemd-networkd[620]: br_ext_sec: Link UP Apr 23 19:39:52 fancy ifup[1538]: Waiting for br_ext_sec to get ready (MAXWAIT is 5 seconds). Apr 23 19:39:52 fancy kernel: [ 24.360953] br_ext_sec: port 1(ext0.10) entered blocking state Apr 23 19:39:52 fancy kernel: [ 24.360956] br_ext_sec: port 1(ext0.10) entered forwarding state Apr 23 19:39:52 fancy systemd[1]: Found device /sys/subsystem/net/devices/br_ext_sec. Apr 23 19:39:52 fancy systemd[1]: Started ifup for br_ext_sec. Apr 23 19:39:52 fancy sh[1547]: ifup: waiting for lock on /run/network/ifstate.br_ext_sec Apr 23 19:39:52 fancy sh[1547]: ifup: interface br_ext_sec already configured Apr 23 19:39:53 fancy systemd-networkd[620]: br_ext_sec: Gained carrier No changes applied to /etc/network/interfaces between boots. No complaints from upgrade process otherwise. Attaching a slightly redacted interfaces file from the system in the ticket aswell. Thanks :) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1874515/+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