Network bonding is used for increasing bandwidth & redundancy. Bonding helps in acting 2 network cards as one. For eg:- if we have 2 network cards say eth0 and eth1 they can both be bonded and act as one interface as bond0.
Linux uses a special kernel module called bonding to allow users to bond multiple network interfaces into a single channel. NIC bonding may also be called NIC Teaming.
Once the bond is configured it acts like any other Ethernet device. For example, you can configure alias interfaces to handle multiple IP addresses.
Round-robin policy: Transmit packets in sequential order from the first available slave through the last. This mode provides load balancing and fault tolerance.
Active-backup policy: Only one slave in the bond is active. A different slave becomes active if, and only if, the active slave fails. The bond’s MAC address is externally visible on only one port (network adapter) to avoid confusing the switch. This mode provides fault tolerance. The primary option affects the behavior of this mode.
XOR policy: Transmit based on [(source MAC address XOR’d with destination MAC address) modulo slave count]. This selects the same slave for each destination MAC address. This mode provides load balancing and fault tolerance.
Broadcast policy: transmits everything on all slave interfaces. This mode provides fault tolerance.
IEEE 802.3ad Dynamic link aggregation. Creates aggregation groups that share the same speed and duplex settings. Utilizes all slaves in the active aggregator according to the 802.3ad specification.
Adaptive transmit load balancing: channel bonding that does not require any special switch support. The outgoing traffic is distributed according to the current load (computed relative to the speed) on each slave. Incoming traffic is received by the current slave. If the receiving slave fails, another slave takes over the MAC address of the failed receiving slave.
Adaptive load balancing: includes balance-tlb plus receive load balancing (rlb) for IPV4 traffic, and does not require any special switch support. The receive load balancing is achieved by ARP negotiation. The bonding driver intercepts the ARP Replies sent by the local system on their way out and overwrites the source hardware address with the unique hardware address of one of the slaves in the bond such that different peers use different hardware addresses for the server.
To configure bond0 you can use the following link which is quite nice.
Even bond0 can help in running multiple instances of jboss & tomcat on the same port.
Feel free to comment for any queries or comments.