bonding lacp port id parameter

Hi All,

I would like to introduce a new feature to bonding driver.
It makes possible to attach more Linux boxes (as member) to a dynamic LAG port (802.1ax or 802.3ad) on a switch.

The patch adds port id setting feature by lacp_port_id module parameter and it's possible to set it by sysfs.

Adding more linux boxes to a LAG makes possible to do load-balancing by using port channel load balancing of switch (eg. by source-dest-ip or src-ip).

It's essential to set the same MAC address to bonding interface and to set different port ids on different Linux boxes for a working solution.

Possible use cases:
1. Redundant DNS servers with same IP address
2. Reverse proxies with same IP address
3. "multi-master" LVS

Beside redundancy it provides scalability, scalability depends on hardware capability.
(E.g. a LAG port with 4 members - linux LVS servers - using a Cisco switch/router splits traffic to ports equally by src IP (2-2-2-2). If a link fails, switch forwards traffic to 3 switch ports (3-3-3). It means you can utilize overall bandwith as much as 66% with full redundancy. It's better with 16% than using 2 master-slave LVS and you use just 1 IP and can handle 100% more peak traffic.)

Using this feature with vPC (virtual portchannel) or similar solution it provides a physically redundant service from network devices to servers. (Nowadays it's available in cheaper network devices - e.g. distributed link aggregation in HP switches.)

-- 
Best regards,
Krisztian IVANCSO
github-ivan@ivancso.net
https://www.ivancso.net