How do I configure network bonding for servers?

Configuring network bonding (also known as NIC teaming or link aggregation) for servers enhances network performance, redundancy, and fault tolerance. Here’s a step-by-step guide to configure network bonding:

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Prerequisites

1. Network Interface Cards (NICs): Ensure your server has at least two physical NICs available for bonding.
2. Switch Configuration: Configure the switch to support bonding/teaming (e.g., LACP for 802.3ad).
3. Root or Admin Access: You must have administrative/root access to the server.

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For Linux Servers

Linux uses bonding drivers to aggregate multiple NICs into a single virtual interface.

Step 1: Install Necessary Packages

Ensure the ifenslave package is installed:
bash
sudo apt install ifenslave # On Debian/Ubuntu
sudo yum install iproute # On RHEL/CentOS

Step 2: Configure Bonding

Edit the network configuration files depending on your Linux distribution.

Debian/Ubuntu

1. Edit the /etc/network/interfaces file:
   “`bash
   auto bond0
   iface bond0 inet static
   address 192.168.1.100
   netmask 255.255.255.0
   gateway 192.168.1.1
   bond-slaves eth0 eth1
   bond-mode 802.3ad
   bond-miimon 100
   bond-xmit-hash-policy layer3+4

auto eth0
iface eth0 inet manual

auto eth1
iface eth1 inet manual
“`

1. Restart networking:
   bash
sudo systemctl restart networking

RHEL/CentOS

1. Create bonding configuration file /etc/sysconfig/network-scripts/ifcfg-bond0:
   bash
DEVICE=bond0
NAME=bond0
TYPE=Bond
BONDING_MASTER=yes
BOOTPROTO=none
IPADDR=192.168.1.100
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
BONDING_OPTS="mode=4 miimon=100 xmit_hash_policy=layer3+4"
ONBOOT=yes

2. Configure slave interfaces /etc/sysconfig/network-scripts/ifcfg-eth0:
   bash
DEVICE=eth0
TYPE=Ethernet
BOOTPROTO=none
MASTER=bond0
SLAVE=yes
ONBOOT=yes

3. Configure /etc/sysconfig/network-scripts/ifcfg-eth1:
   bash
DEVICE=eth1
TYPE=Ethernet
BOOTPROTO=none
MASTER=bond0
SLAVE=yes
ONBOOT=yes

4. Restart the network service:
   bash
sudo systemctl restart network

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Bonding Modes in Linux

Choose a bonding mode based on your requirements:
– mode=0 (balance-rr): Round-robin policy for load balancing and fault tolerance.
– mode=1 (active-backup): One NIC active, others backup (fault tolerance only).
– mode=2 (balance-xor): XOR policy for load balancing.
– mode=3 (broadcast): Sends packets on all NICs (for special use cases).
– mode=4 (802.3ad): Dynamic link aggregation (requires LACP on the switch).
– mode=5 (balance-tlb): Adaptive transmit load balancing.
– mode=6 (balance-alb): Adaptive load balancing for transmit and receive.

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For Windows Servers

Windows uses NIC Teaming for network bonding.

Step 1: Open NIC Teaming

1. Open Server Manager.
2. Go to Local Server.
3. Under Properties, find NIC Teaming and click on it.

Step 2: Create a New Team

1. In the NIC Teaming dialog box, click Tasks → New Team.
2. Select the NICs you want to include in the team.
3. Configure the team properties:
4. Team Name: Specify the name of the team.
5. Teaming Mode: Select:
   • Switch Independent: No configuration required on the switch.
   • LACP: Requires switch configuration for 802.3ad.
   • Static Teaming: Requires manual configuration on the switch.

6. Load Balancing Mode: Choose between address hash or Hyper-V port.

7. Click OK.

Step 3: Assign IP Address

Assign an IP address to the new virtual NIC created by the team.

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Testing and Verification

1. Linux: Check the bond status:
   bash
cat /proc/net/bonding/bond0

2. Windows: Verify the NIC team by checking the network adapter status in Server Manager.

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Important Notes

• Ensure NICs are connected to the same switch or switches that support bonding protocols.
• When using mode=4 (802.3ad) with Linux, enable LACP on the switch ports.
• Test failover by disconnecting one NIC and verifying the server remains reachable.

Let me know if you need help with any specific step or troubleshooting!