How to create a bond interface and VLAN using nmcli

In this short article, we will look at how to create a bond interface and VLAN on top of it using nmcli.

In this example, I have two interfaces eth0 and eth1 which should be aggregated into a logical bond interface. Although there is a trunk, and I need to specify a VLAN ID.

First, we need to create a bond interface:

nmcli con add type bond ifname bond0 \
bond.options "mode=balance-rr,miimon=100" \
ipv4.method disabled \
ipv6.method ignore

I chose balance-rr mode. Other modes you can choose:

• active-backup
• balance-xor
• broadcast
• 802.3ad
• balance-tlb
• balance-alb

Some of them require switch configuration.

Also, I specify ipv4.method disabled and ipv6.method ignore, because I will set up IPv4 network later during VLAN creation. Otherwise, a bond interface can flap and lose packets during the IP address discovery procedure.

Next, we need to add physical interfaces to the bond:

nmcli con add type ethernet ifname eth0 master bond0
nmcli con add type ethernet ifname eth1 master bond0

Next create a VLAN interface on top of the bond and specify an IPv4 address, DNS server, and Domain:

nmcli con add type vlan con-name vlan10 \
dev bond0 \
id 10 \
ip4 192.168.10.10/24 \
gw4 192.168.10.1 \
ipv4.dns 192.168.10.5 \
ipv4.dns-search "vmik.lab"

Where:
dev – device, where VLAN will be created. In this case bond0;
id – VLAN tag (VLAN ID);
ip4 – desirable IPv4 address in CIDR format;
gw4 – default gateway;
ipv4.dns – DNS server for IPv4 network;
ipv4.dns-search – domain, if necessary.

Let’s check the created connections:

nmcli con show
NAME                    UUID                                  TYPE      DEVICE
eth0                   7d743d6f-7257-3c96-a04b-54a61c70eb35  ethernet  eth0
eth1                   403bba70-084c-39de-8c7d-5e9102419de4  ethernet  eth1
vlan10                 c5d6b4b6-1350-4c03-b7e8-c33668db7140  vlan      bond0.10
lo                     a537ee20-73ac-46c2-b2a0-c86c51220bd8  loopback  lo
bond-bond0             bbdbde12-6fad-46e5-b07b-798632399bff  bond      bond0
bond-slave-eth0        c436dd43-f6f3-4ddd-8a18-e74273600797  ethernet  eth0
bond-slave-eth1        9569f990-f720-4ebc-9824-afabf5cee691  ethernet  eth1

From there we can see our physical interfaces and a bond interface, bond-slave, and vlan. If interfaces are connected, they will be highlighted.

That’s all.