Hier der Link zum Original: https://www.unixmen.com/linux-basics-create-network-bonding-on-centos-76-5/
What is Network bonding?
Network bonding is a
method of combining (joining) two or more network interfaces together
into a single interface. It will increase the network throughput,
bandwidth and will give redundancy. If one interface is down or
unplugged, the other one will keep the network traffic up and alive.
Network bonding can be used in situations wherever you need redundancy,
fault tolerance or load balancing networks.
Linux allows us to bond multiple network interfaces into single interface using a special kernel module named bonding. The Linux bonding driver provides a method for combining multiple network interfaces into a single logical “bonded”
interface. The behaviour of the bonded interfaces depends upon the
mode; generally speaking, modes provide either hot standby or load
balancing services. Additionally, link integrity monitoring, may be
performed.
Types of Network Bonding
According the to the official documentation, here is the types of network bonding modes.
mode=0 (balance-rr)
Round-robin policy:
It the default mode. It transmits packets in sequential order from the
first available slave through the last. This mode provides load
balancing and fault tolerance.
mode=1 (active-backup)
Active-backup policy:
In this mode, only one slave in the bond is active. The other one will
become active, only when 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.
mode=2 (balance-xor)
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.
mode=3 (broadcast)
Broadcast policy: transmits everything on all slave interfaces. This mode provides fault tolerance.
mode=4 (802.3ad)
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.
Prerequisites:
– Ethtool support in the base drivers for retrieving the speed and duplex of each slave.
– A switch that supports IEEE 802.3ad Dynamic link aggregation. Most
switches will require some type of configuration to enable 802.3ad mode.
mode=5 (balance-tlb)
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.
Prerequisite:
– Ethtool support in the base drivers for retrieving the speed of each slave.
mode=6 (balance-alb)
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.
In this handy tutorial let us see how to
setup network bonding on CentOS 7 and CentOS 6.5. Though it was tested
on CentOS, it should work on RHEL and Scientific Linux 6.x versions.
First, we will setup network bonding on CentOS 7.
1. Setting up Network Bonding on CentOS 7
Let us combine two NICs (enp0s8, and enp0s9) and make them into one NIC named bond0.
Configure Bond0 Interface
In CentOS 7, the bonding module is not loaded by default. Enter the following command as root user to enable it.
modprobe --first-time bonding
You can view the bonding module information using command:
modinfo bonding
Sample output:
filename: /lib/modules/3.10.0-123.el7.x86_64/kernel/drivers/net/bonding/bonding.ko alias: rtnl-link-bond author: Thomas Davis, tadavis@lbl.gov and many others description: Ethernet Channel Bonding Driver, v3.7.1 version: 3.7.1 license: GPL srcversion: E52AE00A79EA6FEFB5BF718 depends: intree: Y vermagic: 3.10.0-123.el7.x86_64 SMP mod_unload modversions signer: CentOS Linux kernel signing key sig_key: BC:83:D0:FE:70:C6:2F:AB:1C:58:B4:EB:AA:95:E3:93:61:28:FC:F4 sig_hashalgo: sha256 parm: max_bonds:Max number of bonded devices (int) parm: tx_queues:Max number of transmit queues (default = 16) (int) parm: num_grat_arp:Number of peer notifications to send on failover event (alias of num_unsol_na) (int) parm: num_unsol_na:Number of peer notifications to send on failover event (alias of num_grat_arp) (int) parm: miimon:Link check interval in milliseconds (int) parm: updelay:Delay before considering link up, in milliseconds (int) parm: downdelay:Delay before considering link down, in milliseconds (int) parm: use_carrier:Use netif_carrier_ok (vs MII ioctls) in miimon; 0 for off, 1 for on (default) (int) parm: mode:Mode of operation; 0 for balance-rr, 1 for active-backup, 2 for balance-xor, 3 for broadcast, 4 for 802.3ad, 5 for balance-tlb, 6 for balance-alb (charp) parm: primary:Primary network device to use (charp) parm: primary_reselect:Reselect primary slave once it comes up; 0 for always (default), 1 for only if speed of primary is better, 2 for only on active slave failure (charp) parm: lacp_rate:LACPDU tx rate to request from 802.3ad partner; 0 for slow, 1 for fast (charp) parm: ad_select:803.ad aggregation selection logic; 0 for stable (default), 1 for bandwidth, 2 for count (charp) parm: min_links:Minimum number of available links before turning on carrier (int) parm: xmit_hash_policy:balance-xor and 802.3ad hashing method; 0 for layer 2 (default), 1 for layer 3+4, 2 for layer 2+3 (charp) parm: arp_interval:arp interval in milliseconds (int) parm: arp_ip_target:arp targets in n.n.n.n form (array of charp) parm: arp_validate:validate src/dst of ARP probes; 0 for none (default), 1 for active, 2 for backup, 3 for all (charp) parm: fail_over_mac:For active-backup, do not set all slaves to the same MAC; 0 for none (default), 1 for active, 2 for follow (charp) parm: all_slaves_active:Keep all frames received on an interfaceby setting active flag for all slaves; 0 for never (default), 1 for always. (int) parm: resend_igmp:Number of IGMP membership reports to send on link failure (int) create a bond0 configuration file as shown below.
Note: Here, BONDING_OPTS describes the bonding mode. In our case, we will be configuring mode0(active-active). Save and close file. 192.168.1.50 is bond0 IP address.
Configure Network interfaces
Now, we should modify both(enp0s8 & enp0s9) configuration files as shown below. First, let us start from enp0s8.
Now, enter the following command to make Network Manager aware the changes.
nmcli con reload
Restart network service to take effect the changes.
systemctl restart network
Test Network Bonding
Now enter the following command to check whether the bonding interface bond0 is up and running:
cat /proc/net/bonding/bond0
As you see in the above output, the bond0 interface is up and running and it is configured as active-backup(mode1) mode. In this mode, only one slave in the bond is active. The other one will become active, only when the active slave fails.
To view the list of network interfaces and their IP address, enter the following command:
ip addr
That’s it.
Configure multiple IP addresses for bond0
I want to assign multiple IP addresses to bond0 interface. What should i do? Very simple, just create an alias for the bond0 interface and assign multiple IP addresses.
Let me make it more clear. Say for example we want to assign IP address 192.168.1.151 to bond0. To create an alias for bond0, copy the existing configuration file(ifcfg-bond0) to a new configuration file(ifcfg-bond0:1).
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