Link Aggregation
Link aggregation, which is also known as link bonding, joins multiple network interfaces to form a single, unified interface to:
increase throughput, and/or
provide redundancy in case one of the links fails.
Create a bonding
-
In the Services tab, click network setup
to display the current configuration of your network interfaces.
Three network interfaces are defined: lo, eth0, and eth1.
service network lo ip address 127.0.0. service network eth0 auto on ip autoconfig ip address 192.168.0.200/255.255.255.0 ip route default 192.168.0.1 service network eth1 auto on
-
Remove any IP configuration from any interfaces you wish to bond together.
We prepare to bond the eth0 and eth1 interfaces by removing the
ip
rules from them.service network lo ip address 127.0.0.1/9 service network eth0 auto on service network eth1 auto on
-
Use the
service network
directive to create a new interface that will serve as the bonded interface.Set the
bonding primary
directive to the name of the first interfaceSet the
slave
directive to the names of the interfaces that will be bondedSet the
ip address
directive to the IP address to bind to this new interface
We crete a new interface named bond0.
service network lo ip address 127.0.0.1/9 service network eth0 auto on service network eth1 auto on service network bond0 bonding primary eth0 slave eth0 eth1 ip address 172.16.24.237/24
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Configure the bond mode:
Set the
bonding mode
directive to one of the supported bonding mode values.
Failover mode with one active interface at a time
Create a bond0 interface in active/passive mode on top of interfaces eth0 and eth1:
service network eth0 auto on service network eth1 auto on service network bond0 bonding primary eth0 slave eth0 eth1 ip address 172.16.24.237/24 bonding mode active-backup
IEEE 802.3ad (LACP) Dynamic link aggregation
Create a bond0 interface in active/active mode on top of interfaces eth0 and eth1:
service network eth0 auto on service network eth1 auto on service network bond1 bonding primary eth0 slave eth0 eth1 ip address 172.16.24.237/24 bonding mode 802.3ad
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Do one of the following.
If you updated an existing bond interface, reload the network interface.
If you created a new bond interface, restart the network interface.
In the Setup tab, click Save under Local Configuration to persist your changes after a reboot.
Available settings
The following settings are available to configure the bonding interface:
Parameter | Description |
---|---|
slave <iface> <iface>... | interfaces to add in the bond |
bonding primary <iface> | primary slave for current bond |
bonding mode <mode> | bonding mode (default: 1 or active-backup) |
bonding updelay <ms> | bonding delay check in ms (default: 1000) |
bonding downdelay <ms> | bonding delay check in ms (default: 1000) |
Available modes
The following table shows which bonding modes are supported.
Mode number | Mode code | Description |
---|---|---|
O | balance-rr | Select output interfaces in a round-robin fashion. |
1 | active-backup | Failover mode with one active interface at a time. |
2 | balance-xor | Transmit based on MAC address. The default policy is a source+destination MAC address algorithm. You can select alternate transmit policies through the |
3 | broadcast | Not supported. |
4 | 802.3ad | You can bundle several physical ports to form a single logical channel through the Link Aggregation Control Protocol (LACP), which is part of the IEEE specification 802.3ad.
|
5 | balance-tlb | Transmit load balancing. The outgoing interface is selected based on interfaces load.
|
6 | balance-alb | Adaptive load balancing; balance-tlb mode with a reception load balancing mode made using the ARP protocol. |
Troubleshooting
When the bonding configuration is correctly set up:
The bondX interface has at least the MASTER and MULTICAST labels
The ethX interfaces have at least the SLAVE and MULTICAST labels
Both bondX and associated ethX are UP
The bondX and ethX interfaces have the same MAC address
bond0 Link encap:Ethernet HWaddr 00:0D:B9:13:52:2D
inet addr:10.0.32.10 Bcast:0.0.0.0 Mask:255.255.0.0
UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
eth0 Link encap:Ethernet HWaddr 00:0D:B9:13:52:2D
UP BROADCAST NOARP SLAVE MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:11 Base address:0x2000
eth1 Link encap:Ethernet HWaddr 00:0D:B9:13:52:2D
UP BROADCAST NOARP SLAVE MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:12 Base address:0x4000
Advanced parameter: xmit-hash-policy
When used in active/active mode (i.e. bonding mode
is set to 802.3ad), the choice of which network interface to use for outbound traffic is made using the destination MAC address.
In some cases, for example, when the traffic to your default gateway is higher than a single network interface capacity, you can change the xmit-hash-policy
by setting the /sys
parameter.
-
Add a
xmit-hash-policy
directive using the syntax below:bonding xmit_hash_policy <policyid>
The <policyid>
can have two values and describes the information used to compute the hash algorithm:
| Use the destination MAC address |
| When available, use source and destination IPs and ports |
Change xmit_hash_policy
to 1 for bonding1:
service network bond1
slave eth0 eth1
bonding primary eth0
bonding mode 802.3ad
ip address 172.16.24.237/24
bonding xmit_hash_policy 1
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Network Interfaces