Lag Load Sharing; Hash Based Load Sharing - Dell PowerConnect B-RX Configuration Manual

8

LAG load sharing

Figure 15
end of the LAG are on different interface modules.
FIGURE 15
LAG load sharing
device switches can be configured for load sharing over a LAG by using the Hash Based Load
Sharing method.

Hash based load sharing

The device switch shares the traffic load evenly across the ports in LAG group, while ensuring that
packets in the flow are not reordered. Individual flows are assigned a trunk index to identify them.
Traffic from each flow is then distributed across the ports in the LAG group using a hash index as
follows:
•
•
•
232
shows and example of two devices connected over a 4 port LAG where the ports on each
Examples of multi-slot, multi-port LAG
Port2/1
Port1/1
Port2/2
Port1/2
Port2/3
Port1/3
Port2/4
Port1/4
Port2/5
Port1/5
Port2/6
Port1/6
Port2/7
Port1/7
Port2/8
Port1/8
For L2 traffic, the hash index is based on the following:
•
Layer-2 packets with an IPv4 payload: source IPv4 address, source mac addresses,
destination IPv4 address, desination mac address and TCP/UDP source port and
TCP/UDP destination port.
For L3 traffic, the hash index is based on the following:
•
IPv4 non-TCP/UDP packets: source MAC address and destination MAC address, source IP
address and destination IP address
•
IPv4 TCP packets: source MAC address and destination MAC address, source IP address
and destination IP address, and TCP source port and TCP destination port.
•
IPv4 UDP packets: source MAC address and destination MAC address, source IP address
and destination IP address, and UDP source port and UDP destination port.
•
IPv6 non-TCP/UDP packets: source MAC address and destination MAC address, source IP
address and destination IP address.
•
IPv6 TCP packets: source MAC address and destination MAC address, source IP address
and destination IP address, and TCP source port and TCP destination port.
•
IPv6 UDP packets: source MAC address and destination MAC address, source IP address
and destination IP address, and UDP source port and UDP destination port.
For L2 VPN traffic, the hash index is based on the following:
•
Layer-2, non-IPv4.IPv6 packets: source MAC address and destination MAC address.
Port2/1
Port1/1
Port2/2
Port1/2
Port2/3
Port1/3
Port2/4
Port1/4
Port2/5
Port1/5
Port2/6
Port1/6
Port2/7
Port1/7
Port2/8
Port1/8
BigIron RX Series Configuration Guide
53-1001810-01