bonding.ko

The bonding.ko module in Linux is responsible for network interface bonding, which is a technique for combining multiple network interfaces into a single virtual interface. This is typically used for increasing network throughput, providing fault tolerance, and improving network reliability. The bonding.ko kernel module is commonly used with Ethernet interfaces and can be configured to operate in various bonding modes.

Key Features of `bonding.ko`:

Load balancing: Distributes traffic across multiple interfaces to increase throughput.
Failover: Provides redundancy by automatically switching to a backup interface if the active one fails.
Team-based networking: Allows for a single logical interface combining multiple physical interfaces.
Automatic interface failover: Automatically switches to a backup network interface in case of failure.

Loading the `bonding.ko` module

To use network bonding, the bonding.ko module needs to be loaded into the kernel. You can load the module with the following command:

sudo modprobe bonding

To verify that the bonding module is loaded, you can check with:

lsmod | grep bonding

Alternatively, you can check the system logs using dmesg:

dmesg | grep bonding

Module Options for `bonding.ko`

The bonding.ko module can be configured with a variety of options when it is loaded. Here are some common options:

mode=: Defines the bonding mode (load balancing or failover strategy). Valid values are:
- mode=0: Round-robin (balance-rr) - Transmit packets in a round-robin manner across the interfaces.
- mode=1: Active-backup (failover) - One interface is active, and others are backups. If the active interface fails, a backup interface is used.
- mode=2: XOR (balance-xor) - Transmit packets based on the XOR of the MAC address of the sender and receiver, providing load balancing and fault tolerance.
- mode=3: Broadcast - Send all traffic on all interfaces, providing fault tolerance.
- mode=4: 802.3ad (LACP) - Use the IEEE 802.3ad Link Aggregation Control Protocol (LACP) for dynamic link aggregation.
- mode=5: Adaptive transmit load balancing (balance-tlb) - Distribute outbound traffic based on the current load.
- mode=6: Adaptive load balancing (balance-alb) - A combination of both adaptive transmit and receive load balancing.
Example:
```
sudo modprobe bonding mode=1
```
miimon=: Specifies the monitoring frequency for link status, in milliseconds. This is used in modes that require active monitoring of interfaces, such as active-backup, balance-alb, and balance-tlb.
- Example: Monitor the interface link every 100 milliseconds:
```
sudo modprobe bonding miimon=100
```
updelay=: Defines how long to wait before bringing up a backup interface after a failure is detected.
- Example: 200 milliseconds delay before bringing up a backup interface:
```
sudo modprobe bonding updelay=200
```
downdelay=: Defines how long to wait before taking down a failed interface. Typically used in active-backup mode.
- Example: 200 milliseconds delay before taking down a failed interface:
```
sudo modprobe bonding downdelay=200
```
fail_over_mac=: Specifies the MAC address to use for failover purposes in active-backup mode.
- Example:
```
sudo modprobe bonding fail_over_mac=00:11:22:33:44:55
```
arp_interval=: Defines the interval for sending ARP requests when using ARP monitoring in the active-backup mode. This helps in detecting link failure.
- Example: Set ARP interval to 200 seconds:
```
sudo modprobe bonding arp_interval=200
```
arp_ip_target=: Specifies the target IP address for ARP monitoring.
- Example: Monitor the IP address 192.168.1.1 for link failure:
```
sudo modprobe bonding arp_ip_target=192.168.1.1
```
lacp_rate=<fast|slow>: Specifies the rate at which the Link Aggregation Control Protocol (LACP) packets are sent, used in 802.3ad mode.
- fast: Sends LACP packets every 1 second.
- slow: Sends LACP packets every 30 seconds.
- Example:
```
sudo modprobe bonding lacp_rate=fast
```
primary=: Specifies the primary interface in an active-backup configuration. This is the interface that will be used as long as it is up and functional.
- Example:
```
sudo modprobe bonding primary=eth0
```
xmit_hash_policy=: Defines how the outgoing traffic is distributed across the slave interfaces. Common policies include:
- layer2: Use the MAC address for hashing.
- layer3+4: Use the IP addresses and ports for hashing.
- Example:
```
sudo modprobe bonding xmit_hash_policy=layer3+4
```
miimon=: Sets the link monitoring frequency for detecting link failures. Used in most bonding modes, especially in balance-tlb, balance-alb, and active-backup.
```
sudo modprobe bonding miimon=100
```

Example: Configuring Bonding on a System

Here’s an example of how to configure bonding on a system with two network interfaces (eth0 and eth1) using the active-backup mode with monitoring:

sudo modprobe bonding mode=1 miimon=100 updelay=200 downdelay=200 primary=eth0

This would configure bonding with the following settings:

Active-backup mode (mode=1)
Link monitoring every 100 milliseconds (miimon=100)
200 milliseconds delay to bring up a backup interface (updelay=200)
200 milliseconds delay to take down a failed interface (downdelay=200)
eth0 is the primary interface (primary=eth0)

Creating a Bonding Interface Configuration

After loading the bonding module and setting the appropriate options, you can configure the bonding interface in the /etc/network/interfaces file or the systemd network configuration (depending on your system's setup).

For example, the /etc/network/interfaces configuration for bonding might look like this:

# /etc/network/interfaces

# Loopback interface
auto lo
iface lo inet loopback

# Bonding interface eth0 + eth1
auto bond0
iface bond0 inet static
    address 192.168.1.100
    netmask 255.255.255.0
    gateway 192.168.1.1
    bond-mode 1
    bond-miimon 100
    bond-updelay 200
    bond-downdelay 200
    bond-primary eth0
    slaves eth0 eth1

This configuration would create a bonding interface bond0, use eth0 and eth1 as slaves, and apply the previously mentioned bonding settings.

Conclusion

The bonding.ko module allows you to combine multiple network interfaces into one virtual interface for enhanced performance and fault tolerance. It supports various bonding modes, such as active-backup, round-robin, and 802.3ad LACP, and can be configured with a variety of options, including link monitoring, delays, and primary interface settings. The configuration can be done using the modprobe command to set module options or by adding settings to the appropriate network configuration files.

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Last updated 4 months ago

Key Features of bonding.ko:

Loading the bonding.ko module

Module Options for bonding.ko