Traffic From OpenVPN Interface Not Updating On Traffic Graphs When DCO Is Enabled

tman222 · Aug 27, 2023, 6:14 PM

Hi all,

EDIT: The described traffic graphs issue below only occurs if DCO is enabled on the OpenVPN server.

I recently noticed that I do not see the traffic graphs updating for the OpenVPN interface (ovpns1) in the pfSense web GUI. I have an OpenVPN server configured and DCO enabled. VPN connectivity appears to work fine and I do see the VPN traffic updating on the WAN interface traffic graph. If I go to Status -> Traffic Graphs and select the OpenVPN interface I see updates on the right side (Host IP, Bandwidth In, Bandwidth Out), but the graph on the left side still does not update (i.e. continues to stay at zero regardless of the VPN traffic actually being passed).

I'm seeing this exact behavior on two separate systems, both running pfSense Plus 23.05.1 with very similar OpenVPN server configurations (both have DCO enabled and ovpns1 OpenVPN interfaces created). Does anyone have any idea why there is no traffic updating on OpenVPN interface traffic graph? This used to work just fine in prior versions of pfSense, so I'm not sure the issue is related to the latest version and/or enabling DCO. Thanks in advance for your help, I really appreciate it.

johnpoz · Aug 27, 2023, 6:05 PM

@tman222 just tested this, I have not played with dco as of yet.. I am seeing graphs traffic - just got a long ping running and graph of traffic is there along with Ips involved.

I am on 23.05.1

Can you try just turning off dco for test? Or have you tried using the rate vs iftop mode

I could try turning on dco, but haven't even looked into what that entails would even support it. I don't think it makes any sense for me since I use chacha20 and this is in the notes

https://docs.netgate.com/pfsense/en/latest/vpn/openvpn/dco.html

At this time, neither AES-NI nor QAT can accelerate ChaCha20-Poly1305. Some newer QAT hardware may be capable of accelerating ChaCha20-Poly1305, but the current QAT drivers do not yet include support for that encryption algorithm.

tman222 · Aug 27, 2023, 6:12 PM

Thanks @johnpoz - I just turned off OpenVPN DCO on one of the machines, connected with a client, and the traffic graph for the OpenVPN interface worked fine. So this issue looks to be related to enabling DCO - I'll update the post title. Should I raise a bug report on Redmine for this as well?

johnpoz · Aug 27, 2023, 6:16 PM

@tman222 if you can easy duplicate the problem by just enabling or disabling dco - then yeah I would put in a redmine on it. Look to see if one already exist first would be a good idea.

stephenw10 · Aug 27, 2023, 9:11 PM

Hmm, I could have sworn there was already a bug open for that but I can't find one now.

It's known though. The traffic graph data only shows the tunnel management data and not anything that get's offloaded.

tman222 · Aug 27, 2023, 9:26 PM

@stephenw10 said in Traffic From OpenVPN Interface Not Updating On Traffic Graphs When DCO Is Enabled:

Hmm, I could have sworn there was already a bug open for that but I can't find one now.

It's known though. The traffic graph data only shows the tunnel management data and not anything that get's offloaded.

Thanks for confirming @stephenw10. I looked for an existing bug report as well, but couldn't find one so I opened up a new one for it. I guess the upside is that this is one (unintended) way to see whether DCO is enabled and working :).

Thanks again everyone for your help.

Wolf666 · Aug 28, 2023, 10:06 AM

@tman222
I confirm same behavior using OpenVPN client with DCO enabled.
Connection is working pretty fine but traffic graphs are flat.

pfSense 23.05.1

stephenw10 · Aug 28, 2023, 10:14 AM

Yeah this likely is the same thing: https://redmine.pfsense.org/issues/14531