Bond Interfaces (Link Aggregation) in VyOS

A bond (bonding) combines several physical network interfaces into a single logical interface to increase throughput and provide fault tolerance.

Overview

A bond provides:

Increased throughput - link aggregation
Fault tolerance - automatic failover
Load balancing - traffic distribution
Redundancy - link backup

Also known as:

Link Aggregation
Port Channel
EtherChannel (Cisco)
LAG (Link Aggregation Group)
NIC Teaming

Bonding Modes

802.3ad (LACP)

IEEE 802.3ad Dynamic Link Aggregation - the standard aggregation protocol.

set interfaces bonding bond0 mode '802.3ad'
commit

Characteristics:

Requires LACP support on the switch
Automatic detection and configuration
Load balancing
Failover on link failure
Uses all active links

When to use:

Modern managed switches
Standard aggregation is needed
Dynamic configuration is required

active-backup

Only one interface is active; the rest are on standby.

set interfaces bonding bond0 mode 'active-backup'
commit

Characteristics:

The simplest mode
Does not require switch support
Failover only (no load balancing)
Fast switchover on failure

When to use:

The switch does not support aggregation
Only fault tolerance is needed
Simple configuration

balance-rr (Round-Robin)

Sequential packet transmission across all interfaces.

set interfaces bonding bond0 mode 'balance-rr'
commit

Characteristics:

Load balancing
Failover
May cause packet reordering
Does not require switch support

When to use:

Local connection (no switch)
Testing

balance-xor

Hash-based balancing (MAC, IP).

set interfaces bonding bond0 mode 'balance-xor'
set interfaces bonding bond0 hash-policy 'layer2+3'
commit

Characteristics:

Hash-based balancing
Failover
Predictable distribution
Does not require LACP

When to use:

Switch without LACP
Balancing without a protocol is needed

broadcast

Transmission on all interfaces simultaneously.

set interfaces bonding bond0 mode 'broadcast'
commit

Characteristics:

Traffic duplication
Maximum fault tolerance
No throughput increase
Consumes more resources

When to use:

Critical systems
Specific requirements

balance-tlb (Transmit Load Balance)

Outbound traffic balancing without a protocol.

set interfaces bonding bond0 mode 'balance-tlb'
commit

Characteristics:

TX balancing
Failover
Does not require switch support
RX on a single interface

When to use:

More outbound traffic
Switch without aggregation

balance-alb (Adaptive Load Balance)

Balancing of both inbound and outbound traffic.

set interfaces bonding bond0 mode 'balance-alb'
commit

Characteristics:

TX and RX balancing
Uses ARP negotiation
Does not require switch support
IPv4 only

When to use:

Two-way balancing
Switch without LACP
IPv4 traffic only

Basic Configuration

Creating a bond interface

set interfaces bonding bond0 mode '802.3ad'
set interfaces bonding bond0 member interface eth1
set interfaces bonding bond0 member interface eth2
commit

IP addressing

set interfaces bonding bond0 address 192.168.1.1/24
set interfaces bonding bond0 address 2001:db8::1/64
commit

Description

set interfaces bonding bond0 description 'Bonded uplink to core switch'
commit

Configuration Parameters

Member Interfaces

Adding physical interfaces:

set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1
set interfaces bonding bond0 member interface eth2
commit

All member interfaces must have identical parameters (speed, duplex).

Hash Policy

The traffic distribution algorithm (for 802.3ad, balance-xor):

set interfaces bonding bond0 hash-policy 'layer2+3'
commit

Options:

layer2 - uses MAC addresses (default)
layer2+3 - uses MAC + IP addresses
layer3+4 - uses IP + ports (TCP/UDP)

Recommendation: layer2+3 or layer3+4 for better balancing.

LACP Rate

The LACP packet frequency (for 802.3ad only):

set interfaces bonding bond0 lacp-rate 'fast'
commit

Values:

slow - LACP every 30 seconds (default)
fast - LACP every second (fast failure detection)

Recommendation: fast for critical systems.

Minimum Links

The minimum number of active links:

set interfaces bonding bond0 min-links 1
commit

The bond will be UP only if at least the specified number of member interfaces are active.

Primary Interface

The preferred interface (for active-backup):

set interfaces bonding bond0 mode 'active-backup'
set interfaces bonding bond0 primary eth0
commit

ARP Monitoring

Monitoring availability via ARP:

set interfaces bonding bond0 arp-monitor interval 100
set interfaces bonding bond0 arp-monitor target 192.168.1.254
commit

Parameters:

interval - the check interval in milliseconds
target - the IP address to monitor

An alternative to MII monitoring (default).

System MAC

The MAC address of the bond interface:

set interfaces bonding bond0 mac '00:50:56:00:00:01'
commit

By default, it uses the MAC of the first member interface.

VLAN on Bond

A bond can contain VLAN sub-interfaces:

set interfaces bonding bond0 vif 10 address 192.168.10.1/24
set interfaces bonding bond0 vif 10 description 'VLAN 10 - Management'

set interfaces bonding bond0 vif 20 address 192.168.20.1/24
set interfaces bonding bond0 vif 20 description 'VLAN 20 - Data'

commit

Configuration Examples

Basic 802.3ad (LACP) bond

Aggregation of two ports with LACP:

set interfaces bonding bond0 mode '802.3ad'
set interfaces bonding bond0 hash-policy 'layer2+3'
set interfaces bonding bond0 lacp-rate 'fast'
set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1
set interfaces bonding bond0 address 10.0.0.1/24
set interfaces bonding bond0 description 'Uplink to core switch'
commit

Active-backup for fault tolerance

set interfaces bonding bond0 mode 'active-backup'
set interfaces bonding bond0 primary eth0
set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1
set interfaces bonding bond0 address 192.168.1.1/24
commit

Bond with 4 interfaces

set interfaces bonding bond0 mode '802.3ad'
set interfaces bonding bond0 hash-policy 'layer3+4'
set interfaces bonding bond0 lacp-rate 'fast'
set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1
set interfaces bonding bond0 member interface eth2
set interfaces bonding bond0 member interface eth3
set interfaces bonding bond0 min-links 2
set interfaces bonding bond0 address 10.0.0.1/24
commit

Bond with VLANs

# Bond interface
set interfaces bonding bond0 mode '802.3ad'
set interfaces bonding bond0 hash-policy 'layer2+3'
set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1

# VLANs on the bond
set interfaces bonding bond0 vif 100 address 192.168.100.1/24
set interfaces bonding bond0 vif 100 description 'VLAN 100 - Servers'

set interfaces bonding bond0 vif 200 address 192.168.200.1/24
set interfaces bonding bond0 vif 200 description 'VLAN 200 - Workstations'

commit

Bond in a Bridge

Bond as a bridge member for virtualization:

# Bond
set interfaces bonding bond0 mode '802.3ad'
set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1

# Bridge with the bond
set interfaces bridge br0 member interface bond0
set interfaces bridge br0 address 192.168.1.1/24

commit

Dual uplink with ARP monitoring

set interfaces bonding bond0 mode 'active-backup'
set interfaces bonding bond0 primary eth0
set interfaces bonding bond0 member interface eth0
set interfaces bonding bond0 member interface eth1
set interfaces bonding bond0 arp-monitor interval 100
set interfaces bonding bond0 arp-monitor target 10.0.0.254
set interfaces bonding bond0 address 10.0.0.1/24
commit

Switch Configuration

Cisco IOS/IOS-XE

interface Port-channel1
 switchport mode trunk
 switchport trunk allowed vlan 10,20,30

interface GigabitEthernet1/0/1
 switchport mode trunk
 switchport trunk allowed vlan 10,20,30
 channel-group 1 mode active

interface GigabitEthernet1/0/2
 switchport mode trunk
 switchport trunk allowed vlan 10,20,30
 channel-group 1 mode active

Juniper Junos

set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 unit 0 family inet address 10.0.0.2/24

set interfaces ge-0/0/0 ether-options 802.3ad ae0
set interfaces ge-0/0/1 ether-options 802.3ad ae0

Arista EOS

interface Port-Channel1
   switchport mode trunk
   switchport trunk allowed vlan 10,20,30

interface Ethernet1
   channel-group 1 mode active

interface Ethernet2
   channel-group 1 mode active

HP/Aruba

trunk 1-2 trk1 lacp
vlan 10 tagged trk1
vlan 20 tagged trk1

Operational Commands

Viewing bond interfaces

All bond interfaces:

show interfaces bonding

A specific bond:

show interfaces bonding bond0

Detailed information:

show interfaces bonding bond0 detail

Example output:

bond0: <BROADCAST,MULTICAST,MASTER,UP> mtu 1500 state UP
    address: 00:0c:29:ab:cd:ef
    mode: 802.3ad
    hash-policy: layer2+3
    lacp-rate: fast
    min-links: 1

    member interfaces:
        eth0: <SLAVE,UP> speed 1000 duplex full
        eth1: <SLAVE,UP> speed 1000 duplex full

LACP information

show interfaces bonding bond0 lacp

Status of slave interfaces

show interfaces bonding bond0 slaves

Monitoring and Diagnostics

Checking LACP negotiation

show interfaces bonding bond0 lacp detail

Check:

Actor and Partner system ID
LACP activity
The Aggregator ID is the same for all ports

Checking load balancing

show interfaces bonding bond0 statistics

Traffic should be distributed across the member interfaces.

Testing failover

Disable one member interface:

set interfaces ethernet eth0 disable
commit

Check the bond:

show interfaces bonding bond0

Re-enable it:

delete interfaces ethernet eth0 disable
commit

Troubleshooting

Bond does not come up

Check the member interfaces:

show interfaces

All member interfaces must be UP.

Check the configuration:

show configuration interfaces bonding bond0

LACP is not working

Check the switch:

LACP is enabled on the ports
The ports are in the same port-channel
LACP mode: active or passive

Check LACP on VyOS:

show interfaces bonding bond0 lacp

No traffic balancing

Check the hash-policy:

show configuration interfaces bonding bond0 hash-policy

Try a different hash-policy:

set interfaces bonding bond0 hash-policy 'layer3+4'
commit

Make sure there is diversity in the hash (different IPs, MACs, ports).

Frequent failovers

Check the cables and interfaces:

show interfaces ethernet eth0 physical

Increase the LACP rate (if slow is used):

set interfaces bonding bond0 lacp-rate 'fast'
commit

MTU mismatch

Set the same MTU on all member interfaces and the bond:

set interfaces bonding bond0 mtu 9000
commit

Member interfaces inherit the MTU from the bond.

Performance

Maximum throughput

A bond increases the aggregate bandwidth:

2x1G ports = ~2 Gbps
4x1G ports = ~4 Gbps
2x10G ports = ~20 Gbps

Important: A single flow (one TCP session) will not exceed the speed of a single member interface due to hashing.

Hash Policy for better balancing

layer2 - good for different MACs
layer2+3 - better for different IPs
layer3+4 - best for many TCP/UDP connections

Jumbo Frames

For high-performance networks:

set interfaces bonding bond0 mtu 9000
commit

All member interfaces and the switch must support jumbo frames.

Security

MAC Spoofing Protection

A bond uses a single MAC address for all member interfaces.

LACP Authentication

VyOS does not support LACP authentication (802.1X). Use physical security and port security on the switch.

Best Practices

Use 802.3ad (LACP) - standard and reliable
Identical interfaces - the same speed/duplex for all members
LACP fast mode - for fast failover
Min-links - set a minimum number of active links
Hash-policy layer3+4 - for better balancing
Monitoring - track the status of member interfaces
Backup - save the configuration
Test failover - verify switchover
Same MTU - on all members
Document - which ports belong to which bond

Limitations

Maximum throughput is limited by the sum of the member interfaces
A single TCP connection will not exceed the speed of a single interface
LACP requires switch support
Not all modes support RX balancing

Migration from a Single Interface to a Bond

Create a bond with a new name
Move the IP configuration to the bond
Add the member interfaces
Test
Remove the old configuration

Next Steps

Bridge - using a bond in a bridge
VLAN - VLANs on a bond
High Availability - bonds for HA
Firewall - protecting bond traffic

Reviewed by OpenNix LLC · Last updated on 29 July 2026

Bridge Interfaces (L2) in VyOS Tunnel Interfaces (GRE, IPIP) in VyOS