Modifying /etc/network/interfaces to include the following post-up completed networking startup successfully;
auto int0.51 iface int0.51 inet manual vlan-raw-device int0 pre-up ifconfig $IFACE up post-up brctl addbr br_nat_ext 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 auto int0.500 iface int0.500 inet manual vlan-raw-device int0 pre-up ifconfig $IFACE up post-up brctl addbr br_int_500 post-down ifconfig $IFACE down auto br_int_500 iface br_int_500 inet manual bridge_ports int0.500 bridge_maxwait 5 pre-up ifconfig $IFACE up post-down ifconfig $IFACE down Interestingly enough the dhclient also survived (see previous update) when networking completed successfully; root@fancy:/data# ps auxf | grep -i dhclient root 1264 0.0 0.0 99896 5700 ? Ssl 21:59 0:00 /sbin/dhclient -1 -4 -v -i -pf /run/dhclient.br_ext_prim.pid -lf /var/lib/dhcp/dhclient.br_ext_prim.leases -I -df /var/lib/dhcp/dhclient6.br_ext_prim.leases br_ext_prim Both prior boots to this one had no running dhclient after the bridges failed to come up. This should imho be unrelated. -- 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