Link Aggregation is using multiple physical channels in parallel as one logical channel to increase the total capacity of the link and provide redundancy.
For example, it can be used to set up a high-capacity device-to-LAN backbone utilizing two Ethernet interfaces of the device. The total link speed of such backbone will be a sum of the speeds of the Ethernet interfaces. Moreover, in case of one Ethernet connection failure its traffic will be passed to the other one without stooping the services. If later the fallen Ethernet connection will be reestablished the traffic will be sent over both Ethernet interfaces again.
Infinet Wireless LACP (Link Aggregation Control Protocol) realization fully complies with the IEEE 802.3ad standard for link aggregation. In addition, special proprietary LACP mode can be enabled that provides enhancement of the efficiency of the process over the standard mode.
For LACP configuration on IW devices the “lag” command is used.
Syntax:
lag N [command] [(port|-port) (IFNAME | IFNAME...)]
Command:
- "status" - show lag interface status
- "migrate" - enable session migrate
- "-migrate" - disable session migrate
- "balance" - enable session-oriented load balancing
- "-balance" - disable session-oriented load balancing
- "mode" - switch lag inteface mode. Modes: (stand|fast)
- "clear" - remove lag interface from configuration
- "loadm" - show realtime per-port load status.
To enable link aggregation on the device the following command is used:
lag N port (IFNAME | IFNAME...)]
This command creates logical “lagN” interface in the system and assigns parent physical interfaces to it.
Example,
lag 1 port eth0 eth1
In this example “lag1” interface is created and two Ethernet interfaces of the device are assigned.
To delete one ore more parent interfaces from LACP configuration the “-port” option is used. For example,
lag 1 -port eth1
The following commands are used to manage LACP operation and get the statistics:
- "lag N status" – allows to view the aggregation id, the load on each of the parent interfaces and its status
- "lag N migrate / lag N -migrate" – allows/disallows existing sessions migration between the available parent interfaces in case of the difference in the overload. By default, migration is allowed
- "lag N balance / lag N -balance" – allows/disallows load-depending dispersion of new-coming sessions between the available parent interfaces. By default, balancing is enabled
- "lag N mode" – allows to set “standard” or “fast” LACP mode. In “standard” mode LACP acts in accordance to the IEEE 802.3ad standard. In “fast” mode LACP uses IW proprietary extension that enhances its speed of response on the link state changes, optimizes the overall aggregate system performance and delivers more accurate statistics
- "lag N clear" – removes the “lagN” interface from the device configuration
- "lag N loadm" – shows the load statistics in real time on each of the parent interfaces.