devurandom
Hey guys,
So I have an openvpn server at location A. I have a openvpn "router" build that servers as a vpn client to location A but also serves as a dhcp server and does the routing for devices in location B through the VPN tunnel for connectivity back to location A. Everything works fine but when doing performance testing I noticed something very strange.
When running the iperf test from the vpn client box in location B I get a slower speed about 28.2 Mbits/sec and this is consistent and repeatable. But when I run iperf from one of the internal clients at location B that is routing first through the vpn client box, I get a faster speed. This does not make sense to me. I ran multiple test and get consistent results. Here they are:
[ 4] local 192.168.21.20 port 5001 connected with 192.168.18.6 port 37432
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-120.1 sec 1.18 GBytes 84.7 Mbits/sec
[ 4] local 192.168.21.20 port 5001 connected with 192.168.18.6 port 37076
[ 4] 0.0-120.1 sec 401 MBytes 28.0 Mbits/sec
[ 4] local 192.168.21.20 port 5001 connected with 192.168.18.6 port 37078
[ 4] 0.0-120.2 sec 402 MBytes 28.1 Mbits/sec
[ 4] local 192.168.21.20 port 5001 connected with 192.168.18.6 port 37434
[ 4] 0.0-120.1 sec 1.27 GBytes 90.8 Mbits/sec
[ 4] local 192.168.21.20 port 5001 connected with 192.168.18.6 port 37080
[ 4] 0.0-120.2 sec 404 MBytes 28.2 Mbits/sec
[ 4] local 192.168.21.20 port 5001 connected with 192.168.18.6 port 37096
[ 4] 0.0-120.2 sec 402 MBytes 28.0 Mbits/sec
The 28.0 Mbits/sec are the tests run from the vpn client box. The 84.7 Mbits/sec - 90 Mbits/sec results are from the location B internal network, attached to the vpn client box.
Does anyone have any ideas why this is happening and also how can everythig to run at 84.7 Mbits/sec - 90 Mbits/sec.
Thanks!
TinCanTech
Possibly, running openvpn and iperf on the one device is to much for it .. but that is only a guess.
devurandom
I ran some more tests. Same results. Htop and other monitor tools like dstat show load is at about 40% on 1 core even when running iperf. This is a 4 core box.
I'm willing to look into any further ideas if you have anything else I can /should check.
I'm running UDP tunneling. The only thing I can think is that I'm using fast-io, and maybe requests coming in from a port are being handled differently by the kernel then requests sourcing directly from this box and this is causing the speed difference?
TinCanTech
Without being witness to your network, I have no idea.
