Score:0

Extraneous bridges preventing internet access

in flag

Recently my Ubuntu install (22.04) has been creating around 5-6 bridge networks, these seem to prevent internet access. I can manually go through and take down each interface and delete the bridge via "brctl delbr", but it's a pain to go through this each time. Even on restart these bridges are re-created.

This is the output of route when the bridges (all the br-* interfaces) are active and preventing internet access:

➜  ~ route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         192.168.0.1     0.0.0.0         UG    600    0        0 wlp0s20f3
link-local      0.0.0.0         255.255.0.0     U     1000   0        0 wlp0s20f3
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0
172.18.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-d426659a2acb
172.19.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-fc0b0e819621
172.20.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-28a1cb513e25
172.21.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-a453127c4011
172.23.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-d80fc876a9ed
192.168.0.0     0.0.0.0         255.255.255.0   U     600    0        0 wlp0s20f3
192.168.0.0     0.0.0.0         255.255.240.0   U     0      0        0 br-238ff410ee26

Here's the output of syslog for one of the bridge interfaces:

Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.1071] manager: (br-d80fc876a9ed): new Bridge device (/org/freedesktop/NetworkManager/Devices/9)
Nov  8 18:25:06 willis-laptop avahi-daemon[1530]: Joining mDNS multicast group on interface br-d80fc876a9ed.IPv4 with address 172.23.0.1.
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2016] device (br-d80fc876a9ed): state change: unmanaged -> unavailable (reason 'connection-assumed', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2026] device (br-d80fc876a9ed): state change: unavailable -> disconnected (reason 'connection-assumed', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop avahi-daemon[1530]: New relevant interface br-d80fc876a9ed.IPv4 for mDNS.
Nov  8 18:25:06 willis-laptop avahi-daemon[1530]: Registering new address record for 172.23.0.1 on br-d80fc876a9ed.IPv4.
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2042] device (br-d80fc876a9ed): Activation: starting connection 'br-d80fc876a9ed' (12323e12-58ee-427c-9b11-967ff562ba1a)
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2063] device (br-d80fc876a9ed): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2072] device (br-d80fc876a9ed): state change: prepare -> config (reason 'none', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2076] device (br-d80fc876a9ed): state change: config -> ip-config (reason 'none', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2107] device (br-d80fc876a9ed): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2274] device (br-d80fc876a9ed): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2277] device (br-d80fc876a9ed): state change: secondaries -> activated (reason 'none', sys-iface-state: 'external')
Nov  8 18:25:06 willis-laptop NetworkManager[1536]: <info>  [1667960706.2284] device (br-d80fc876a9ed): Activation: successful, device activated.
Score:0
in flag

This is almost certainly related to docker setting up too many bridges (see How to determine identity of obscure `nic:br-` devices in powertop?). One solution was to take down an extraneous docker networks:

docker network prune
I sit in a Tesla and translated this thread with Ai:

mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.