I have OpenWRT 15.05 chaos calmer running in router mode with gigabit ethernet ports. I connected a wired client to LAN port and another wired client to WAN port. Added static IP to WAN port and wired client connected to WAN port. Now, LAN client is able to ping wired client attached to WAN port.
Started iPerf traffic with WAN client as iperf server and LAN client as iperf client. Was able to achieve ~850 Mbps.
I added the below rules in /etc/config/firewall and restarted firewall because I wanted to reverse the traffic. That is, iperf server will be in LAN side and iperf client will be in WAN side.
config forwarding
option src lan
option dest wan
But I am seeing only 200 Mbps this way. Need help to understand what is stopping the traffic flow here.
Not the answer you are looking for, as I don't know that, but I suggest you upgrade to 18.06.02. Chaos Calmer is quite outdated and could be vulnerable (particularity if you are allowing forwarding).
Devices: Ubuntu 16.04 machines connected as wired clients in LAN and WAN
Commands: iperf -s & iperf -c server ip
NAT is enabled. Traffic started from client attached to LAN is NAT translated and leaves WAN port to reach client attached to WAN.
CPU utilization looks usual and no surge observed.
Have one thought right now. HW NAT module is enabled and when i remove the module, I am seeing 850 Mbps drop to 200 Mbps. Could it be because HW NAT is not working for the reverse traffic.