Home / server / Questions / 995962
In Process
John Tate
Asked: 2019-12-18 17:47:35 +0800 CST

Removing config defaults for a slave interface of a bridge

  • 772

I am running Fedora 31 and am having trouble with NetworkManager. I tried to make a bond of two ethernet interfaces and then put the bond in a bridge, yet the bond is getting an IPv4 address with DHCP and an IPv6 one statelessly. This means the bridge does not get the address I configured it to have, and does not work.

I added the ethernet interfaces to the configuration...

nmcli con add type ethernet ifname enp6s0 master bond0
nmcli con add type ethernet ifname enp0s31f6 master bond0

Then I added them as slaves to the bond...

nmcli dev mod bond0 +bond.options "active_slave=enp6s0"                                       
nmcli dev mod bond0 +bond.options "active_slave=enp0s31f6"

I created the bridge and made the bond a slave of that...

nmcli con add type bridge ifname brbond0
nmcli con add type bridge-slave ifname bond0 master brbond0

I set the IPv4 & IPv6 settings for the bridge interface...

nmcli con mod bridge-brbond0 ifname brbond0 ip4 192.168.1.4 gw4 192.168.1.1 ipv4.dns "192.168.1.7 192.168.1.8"
nmcli con mod bridge-brbond0 ipv6.method auto

Then I brought up the bond and the bridge in order...

nmcli con up bond-bond0
nmcli con up bridge-brbond0

As you can see the bond0 interface has some defaults I need to get rid of...

5: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ae:d1:55:b4:20:8d brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.211/24 brd 192.168.1.255 scope global dynamic noprefixroute bond0
       valid_lft 3360sec preferred_lft 3360sec
    inet6 2001:XXXX:XXXX:XXXX:XXXX:d3a2:dcd1:7f75/64 scope global dynamic noprefixroute 
       valid_lft 86267sec preferred_lft 14267sec
    inet6 fe80::1e7:fb60:1d99:dabd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

And the bridge interface doesn't have its configuration...

16: brbond0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether ee:98:f9:dc:e3:c8 brd ff:ff:ff:ff:ff:ff

I have not managed to find on Google how to use nmcli to remove the defaults for the bond0 interface. I need the bond on a bridge for my KVM/QEMU virt-manager guests.

There are guides involving editing network-scripts but this is not how I want to do it. I want to solve this issue with nmcli and learn something.

networking

1 Answers

  1. The issue is that the bond0 device had to be converted into a bridge slave. I had simply just created the bridge. As such one just has to modify the bond0 interface. To do this you need your bridge uuid.

    nmcli con edit bond-brbond0
> set connection.slave-type bridge
> set connection.master 88c688aa-9f03-45e2-979e-7f4456a7635b
> verify fix
> save

    After doing this and starting the bridge the system is now working and I can use KVM/QEMU and the issue is solved without editing ifcfg files.

    • 0