From mboxrd@z Thu Jan 1 00:00:00 1970 From: peter.mueller@ipfire.org To: development@lists.ipfire.org Subject: Re: Extremely poor OpenVPN performance, help wanted Date: Wed, 25 Sep 2019 19:13:00 +0000 Message-ID: <1efd8fbe-ddbd-65ab-a0c0-2985ec581b43@ipfire.org> In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8928688641772599854==" List-Id: --===============8928688641772599854== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Hello Tom, thank you for your reply. Yes, these VMs are all running on FreeBSD. I will try to test it with a Debian machine within the next days. While I am pretty sure MTU is not the (only) root cause of this problem, setting it to 1492 bytes on the VMs (interface setting was 1500 bytes) causes a slight improvement to ~ 1.1 MB/sec, which is still way too low. Disabling remote packet filters did not change anything, both VMs and IPFire machine have AES-NI available, thus being able to encrypt a much bigger volume per second (~ 2.1 Gbit/sec on VMs, ~ 267 Mbit/sec on IPFire host). Changing the OpenVPN tunnel MTU to lower values (tested with 1350 and 1300 bytes) did not change anything. Thanks, and best regards, Peter M=C3=BCller > Peter, >=20 > Is the issue reproducible on different OS and different OpenVPN clients? Th= ere=E2=80=99s a chance that the issue lies with FreeBSD or how you are config= uring the VMs at different locations. >=20 > Tom >=20 >> On Sep 24, 2019, at 9:23 AM, wrote: >> >> Hello list, >> >> as mentioned several times before, I am experiencing OpenVPN performance >> problems. Since I am out of ideas by now, asking here to help seemed to >> make sense to me, as I am not sure whether it can be traced to a bug or no= t. >> >> Test setup is as follows: >> (a) IPFire is freshly installed on a testing machine with Core Update 135 = (x86_64). >> The machine is connected to the internet via DSL (link has 100 Mbit/sec >> down capacity with MTU set to 1492) and runs dial-in by itself. No >> cascading router or NAT in place here. >> (b) The remote part is a VM hosted at a big German hosting company, with >> FreeBSD 12 installed (OpenVPN 2.4.7). Uplink is 1 Gbit/sec with MTU =3D >> 1492. >> (c) Both systems are able to submit ICMP packets up to 1492 bits, so MTU >> is set correctly on both interfaces. >> (d) The VM is establishing an OpenVPN roadwarrior connection to the IPFire >> machine, which can be set up successfully and uses AES-256-GCM (SHA 512) >> for data channel. Tunnel MTU is set to 1400 bytes. >> >> Downloading a test file via SCP from the VM using the OpenVPN connection >> takes ages and results in throughput between 400 and 700 kB/sec. While >> normal ICMP latency through the tunnel is around 35 ms, it fluctuates betw= een >> 40 and 500 ms while download is running. >> >> Needless to say, a bandwidth of 700 kB/sec is unacceptable. Disabling >> Suricata speeds up to ~ 1.2 MB/sec, disabling Quality of Service (QoS) >> does not have any big effects. >> >> Since there are some clients using OpenVPN in restricted environments, >> TCP and port 443 is more or less fixed. Switching to UDP causes a small >> improvement (~ 800 kB/sec), but does not seem to cure the root cause. >> >> This effect is reproducible with multiple VMs at multiple locations, >> so I do not think it is related to network outages at one certain hoster. >> >> What am I doing wrong? Is anyone experiencing the same problem? >> >> As mentioned in the Subject line, any help is appreciated. >> >> Thanks, and best regards, >> Peter M=C3=BCller --===============8928688641772599854==--