Networking [SOLVED]: network down when adding bridge

Networking [SOLVED]: network down when adding bridge

Home Forums Networking Networking [SOLVED]: network down when adding bridge

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
    Posts
  • #35265

    Anonymous

    QuestionQuestion

    I am trying to get a VM accessible to other computers that are on the same network as enp3s0 which is my ethernet interface.

    the idea is to create a bridge for it, so my /etc/network/interfaces looks like this:

    # The loopback network interface
    auto lo
    iface lo inet loopback
    
    # The primary network interface
    auto enp3s0
    iface enp3s0 inet static
    address 192.168.1.111
    netmask 255.255.255.0
    network 192.168.1.0
    broadcast 192.168.1.255
    gateway 192.168.1.254
    dns-nameservers 192.168.1.254 8.8.8.8
    
    auto brx
    iface brx inet static
      address 192.168.1.1
      network 192.168.1.0
      netmask 255.255.255.0
      broadcast 192.168.1.255
      bridge_ports enp3s0
    

    I lose access to the host machine, once I save that file and reload the networking service using: service networking restart.

    I have access to the host machine using ssh, and it’s painful to debug.

    here is the result of ipt addr:

    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
        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: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
        link/ether d8:cb:8a:7e:b0:0e brd ff:ff:ff:ff:ff:ff
        inet 192.168.1.111/24 brd 192.168.1.255 scope global enp3s0
           valid_lft forever preferred_lft forever
        inet6 fe80::dacb:8aff:fe7e:b00e/64 scope link 
           valid_lft forever preferred_lft forever
    3: bond0: <BROADCAST,MULTICAST,MASTER> mtu 1500 qdisc noop state DOWN group default qlen 1000
        link/ether de:d1:a5:18:d7:9e brd ff:ff:ff:ff:ff:ff
    4: wlp4s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
        link/ether 60:57:18:ed:85:91 brd ff:ff:ff:ff:ff:ff
    5: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
        link/ether 52:54:00:f1:90:4d brd ff:ff:ff:ff:ff:ff
        inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
           valid_lft forever preferred_lft forever
    6: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
        link/ether 52:54:00:f1:90:4d brd ff:ff:ff:ff:ff:ff
    7: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:ca:92:29:7b brd ff:ff:ff:ff:ff:ff
        inet 172.17.0.1/16 scope global docker0
           valid_lft forever preferred_lft forever
        inet6 fe80::42:caff:fe92:297b/64 scope link 
           valid_lft forever preferred_lft forever
    8: br-55921dfae2b9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:d2:f2:fd:9c brd ff:ff:ff:ff:ff:ff
        inet 172.27.0.1/16 scope global br-55921dfae2b9
           valid_lft forever preferred_lft forever
        inet6 fe80::42:d2ff:fef2:fd9c/64 scope link 
           valid_lft forever preferred_lft forever
    9: br-6126f091366d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:fd:89:f7:3e brd ff:ff:ff:ff:ff:ff
        inet 172.21.0.1/16 scope global br-6126f091366d
           valid_lft forever preferred_lft forever
        inet6 fe80::42:fdff:fe89:f73e/64 scope link 
           valid_lft forever preferred_lft forever
    10: br-79007a99672c: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
        link/ether 02:42:f2:63:b4:a8 brd ff:ff:ff:ff:ff:ff
        inet 172.22.0.1/16 scope global br-79007a99672c
           valid_lft forever preferred_lft forever
    11: br-90998da5c46b: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:40:01:23:c5 brd ff:ff:ff:ff:ff:ff
        inet 172.26.0.1/16 scope global br-90998da5c46b
           valid_lft forever preferred_lft forever
        inet6 fe80::42:40ff:fe01:23c5/64 scope link 
           valid_lft forever preferred_lft forever
    12: br-d2baef82036f: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
        link/ether 02:42:d3:e8:9a:4d brd ff:ff:ff:ff:ff:ff
        inet 172.20.0.1/16 scope global br-d2baef82036f
           valid_lft forever preferred_lft forever
    13: br-af8f996c43db: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
        link/ether 02:42:9f:b0:55:3d brd ff:ff:ff:ff:ff:ff
        inet 172.19.0.1/16 scope global br-af8f996c43db
           valid_lft forever preferred_lft forever
    14: br-ca2d4fcf9238: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:90:b8:b5:b0 brd ff:ff:ff:ff:ff:ff
        inet 172.18.0.1/16 scope global br-ca2d4fcf9238
           valid_lft forever preferred_lft forever
        inet6 fe80::42:90ff:feb8:b5b0/64 scope link 
           valid_lft forever preferred_lft forever
    15: br-e7fe7e040ae1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
        link/ether 02:42:48:58:a9:65 brd ff:ff:ff:ff:ff:ff
        inet 172.30.0.1/16 scope global br-e7fe7e040ae1
           valid_lft forever preferred_lft forever
    17: vethbda138d@if16: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
        link/ether ea:b7:62:85:c5:37 brd ff:ff:ff:ff:ff:ff link-netnsid 0
        inet6 fe80::e8b7:62ff:fe85:c537/64 scope link 
           valid_lft forever preferred_lft forever
    19: veth4b4c337@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-6126f091366d state UP group default 
        link/ether f2:7a:3d:06:a2:cf brd ff:ff:ff:ff:ff:ff link-netnsid 2
        inet6 fe80::f07a:3dff:fe06:a2cf/64 scope link 
           valid_lft forever preferred_lft forever
    21: vethd3629c0@if20: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-6126f091366d state UP group default 
        link/ether 7e:b6:9d:57:ff:cc brd ff:ff:ff:ff:ff:ff link-netnsid 6
        inet6 fe80::7cb6:9dff:fe57:ffcc/64 scope link 
           valid_lft forever preferred_lft forever
    23: veth8c752ba@if22: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-90998da5c46b state UP group default 
        link/ether 4e:28:c4:34:84:6a brd ff:ff:ff:ff:ff:ff link-netnsid 5
        inet6 fe80::4c28:c4ff:fe34:846a/64 scope link 
           valid_lft forever preferred_lft forever
    27: vethe4c8f38@if26: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-ca2d4fcf9238 state UP group default 
        link/ether f6:1f:d4:3c:5a:89 brd ff:ff:ff:ff:ff:ff link-netnsid 1
        inet6 fe80::f41f:d4ff:fe3c:5a89/64 scope link 
           valid_lft forever preferred_lft forever
    29: veth1e8562f@if28: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-ca2d4fcf9238 state UP group default 
        link/ether ca:a9:2f:24:50:54 brd ff:ff:ff:ff:ff:ff link-netnsid 3
        inet6 fe80::c8a9:2fff:fe24:5054/64 scope link 
           valid_lft forever preferred_lft forever
    33: veth243205b@if32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-55921dfae2b9 state UP group default 
        link/ether 52:55:7f:6e:71:ed brd ff:ff:ff:ff:ff:ff link-netnsid 7
        inet6 fe80::5055:7fff:fe6e:71ed/64 scope link 
           valid_lft forever preferred_lft forever
    41: vethabea4e4@if40: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
        link/ether 46:1a:a7:f4:85:40 brd ff:ff:ff:ff:ff:ff link-netnsid 9
        inet6 fe80::441a:a7ff:fef4:8540/64 scope link 
           valid_lft forever preferred_lft forever
    47: veth9e911aa@if46: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-55921dfae2b9 state UP group default 
        link/ether 16:c5:5a:58:21:2d brd ff:ff:ff:ff:ff:ff link-netnsid 10
        inet6 fe80::14c5:5aff:fe58:212d/64 scope link 
           valid_lft forever preferred_lft forever
    

    #35266

    Anonymous

    Accepted AnswerAnswer

    You need to move all the physical device config to the bridge and set the phys dev to “manual”. The bridge device becomes the network device you use instead of the phys dev.

    # The loopback network interface
    auto lo
    iface lo inet loopback
    
    # The primary network interface
    auto enp3s0
    iface enp3s0 inet manual
    
    auto brx
    iface brx inet static
    address 192.168.1.111
    netmask 255.255.255.0
    network 192.168.1.0
    broadcast 192.168.1.255
    gateway 192.168.1.254
    dns-nameservers 192.168.1.254 8.8.8.8
    bridge_ports enp3s0
    

    I don’t know what kind of VMs you’re using but this is the setup I use for containers in LXD.

    Source: https://serverfault.com/questions/886033/network-down-when-adding-bridge
    Author: mjb2kmn
    Creative Commons License
    This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Viewing 2 posts - 1 through 2 (of 2 total)

You must be logged in to reply to this topic.