The SSG can act as a traffic balancer based on IP addresses belonging to an AS defined as local in asnum.dscp.
In this case, the SSG-LB acts as an L2-bridge in the network, hence the name L2 traffic balancer.

Suppose a 400Gbps traffic mirror needs to be evenly distributed among four VAS platforms (Value-Added Services) performing traffic analysis and various detection.
In this case, SSG-LB will evenly distribute traffic with equal port utilization on the pullers and maintain traffic symmetry (traffic from one session will be directed to only one puller).

Example configuration /etc/dpi/fastdpi.conf:

• Traffic mirroring is fed into 4x100G interfaces.
• Traffic is balanced between four pullers, each puller is connected by 4x25G links.

in_dev=05-00.0:05-00.1:05-00.2:05-00.3
out_dev=01-00.0:01-00.1:01-00.2:01-00.3:02-00.0:02-00.1:02-00.2:02-00.3:03-00.0:03-00.1:03-00.2:03-00.3:04-00.0:04-00.1:04-00.2:04-00.3
 
#FastDPI Control
ctrl_port=29000
ctrl_dev=lo
 
#Turn on Load Balancing
enable_l2_lb=1
 
#Balance algorithm
maglev=2
 
#Hash table
lb_hash_out_dev_type=1

Balancing applies only to IP addresses belonging to the AS defined as local in asnum.dscp.

1. Define an autonomous system with IP addresses that are used by subscribers:

   vi aslocal.txt
   10.0.0.0/8 64511
   172.16.0.0/12 64511
   192.168.0.0/16 64511
   cat aslocal.txt | as2bin /etc/dpi/aslocal.bin

   1. Examples for IPv4
   2. Example for IPv6
2. Mark a given autonomous system as local:

   vi my_as_dscp.txt
   64511 local
   10415 local
   cat my_as_dscp.txt | as2dscp /etc/dpi/asnum.dscp

   You can use either a custom AS or a public AS as the AS.
   Read more at the link

3. A reload must be performed to apply the parameters:

   service fastdpi reload

1. Define the input and output interfaces in the configuration file.
   The input interfaces to which the traffic mirror is fed are specified in the in_dev parameter, and the output interfaces are specified in out_dev.
   Interfaces do not form pairs and species constructs are allowed:

   in_dev=05-00.0:05-00.1:05-00.2:05-00.3:0b-00.0:0b-00.1:0b-00.2:0b-00.3
   out_dev=08-00.0:08-00.1:08-00.2:08-00.3

   Or

   in_dev=05-00.0
   out_dev=out_dev=08-00.0:08-00.1:08-00.2:08-00.3

2. Enable balancing mode in the enable_l2_lb parameter, where:
   • 0 — deactivate balancing;
   • 1 — activate balancing.
3. Determine by what value to initialize the hash table in the lb_hash_out_dev_type parameter, where:
   • 0 — use the internal index of the output interface;
   • 1 — use the interface name from [in|out]_dev.
4. Select an engine to handle thread dispatchers in the dpdk_engine parameter, where:
   • 0 — read/write default engine, one dispatcher for everything;
   • 1 — read/write engine with two dispatcher threads: a dispatcher for each direction;
   • 2 — Read/write engine with RSS support: for each direction, dpdk_rss dispatchers are created (default dpdk_rss=2), so total number of dispatchers = 2 * dpdk_rss.
     Learn more about the dpdk_engine parameter by clicking here.
5. Select a balancing algorithm. The maglev algorithm with fixed hash table size is used for traffic balancing, where:
   • 1 — if src and dst ip are both local, then hash is calculated based on these two addresses;
   • 2 — if only src ip local, then hash is calculated based on src ip;
   • 3 — if only dst ip local, hash is calculated on the basis of dst ip;
   • 4 — hash is calculated based on src and dst ip.
     
     Based on the calculated hash value, the output interface is determined by determining the index of the hash table cell containing the interface index from the array of output interfaces.