A speed test with Iperf , Relayd and PF.

[Woden27]

Hi all,

I am conducting some speed test inside my LAN evironment .
The actual testing network topology is as follow :

Iperf Client --> OpenBSD7.1 Proxy --> host server iperf

All the connections are with CAT 6 and running at 1000 Mbps speed .(1Gbps)

The interface 10.10.10.2 is em0 or the interface facing the outside.
The IP address of the iperf server is part of the network behind the Relay
with an address of 192.168.20.9.

With Iperf from the server side, I am using the default TCP window size (128KByte), as well from the client side .

When I use this relay with RELAYD :

tcp connection fixup {
  tcp nodelay
}

relay IPERF_TEST{
  listen on 10.10.10.2 port 6740 
  forward to 192.168.20.9 port 6670
  protocol fixup
}

With IPERF I obtain a speed of 144Mbps .

If instead, I deactivate the relayd function and using a simple PF redirecting with

pass in on em0 proto {tcp} from any to em0 port 6740 rdr-to 192.168.20.9 port 6670

I obtain a speed of 892 Mbps.

(which I should expect the same as normal for being a 1Gbps link)

This make me wonder now why using RELAYD makes the TCP redirection so slow and how to improve it since I will need to use Relayd for a HTTP-->HTTPS redirect for example using SNI for different domains.