pfSense » pfSense Plus

It would help to know a few things, such as:

• Is DCO enabled or disabled?
• Is OpenVPN in tap or tun mode?
• Hardware platform

In my case:

DCO enabled
Tun mode
Platform 5100

I ran another test and this time, I disabled DCO. The traffic Graph widget was showing traffic.

The problem only occurs when DCO is enabled.

I tested this with AES-128-GCM and DCO enabled and the Status --> Traffic Graphs still show traffic normally for me. Still not able to confirm this. I ran an iPerf test across an OpenVPN link and was able to see the link saturated on the traffic graph as normal.

There is likely some other configuration factor contributing here then, such as tun/tap, subnet size, topology, etc. Though some of those are limited when DCO is in use, it's still worth expanding on which exact options are selected when it does/doesn't work.

I tested again on a VM hosted on ProxMox with the factory default config file and the OpenVPN configured through the wizard using mostly default values.

Here is the Server Config when the Traffic Graphs widget shows a flat line.

dev ovpns1
verb 1
dev-type tun
dev-node /dev/tun1
writepid /var/run/openvpn_server1.pid
#user nobody
#group nobody
script-security 3
daemon
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
proto udp4
auth SHA256
up /usr/local/sbin/ovpn-linkup
down /usr/local/sbin/ovpn-linkdown
client-connect /usr/local/sbin/openvpn.attributes.sh
client-disconnect /usr/local/sbin/openvpn.attributes.sh
local 192.168.33.10
tls-server
server 10.0.8.0 255.255.255.0
client-config-dir /var/etc/openvpn/server1/csc
username-as-common-name
plugin /usr/local/lib/openvpn/plugins/openvpn-plugin-auth-script.so /usr/local/sbin/ovpn_auth_verify_async user TG9jYWwgRGF0YWJhc2U= false server1 1194
tls-verify "/usr/local/sbin/ovpn_auth_verify tls 'OpenVPN_Cert' 1" 
lport 1194
management /var/etc/openvpn/server1/sock unix
push "dhcp-option DNS 8.8.8.8" 
push "redirect-gateway def1" 
capath /var/etc/openvpn/server1/ca
cert /var/etc/openvpn/server1/cert
key /var/etc/openvpn/server1/key
dh /etc/dh-parameters.2048
tls-auth /var/etc/openvpn/server1/tls-auth 0
data-ciphers AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305
data-ciphers-fallback AES-256-GCM
allow-compression no
persist-remote-ip
float
topology subnet
explicit-exit-notify 1

Here is the server config when the Trafic Graph shows the corresponding values to the speed test measures.

dev ovpns1
disable-dco
verb 1
dev-type tun
dev-node /dev/tun1
writepid /var/run/openvpn_server1.pid
#user nobody
#group nobody
script-security 3
daemon
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
proto udp4
auth SHA256
up /usr/local/sbin/ovpn-linkup
down /usr/local/sbin/ovpn-linkdown
client-connect /usr/local/sbin/openvpn.attributes.sh
client-disconnect /usr/local/sbin/openvpn.attributes.sh
local 192.168.33.10
tls-server
server 10.0.8.0 255.255.255.0
client-config-dir /var/etc/openvpn/server1/csc
username-as-common-name
plugin /usr/local/lib/openvpn/plugins/openvpn-plugin-auth-script.so /usr/local/sbin/ovpn_auth_verify_async user TG9jYWwgRGF0YWJhc2U= false server1 1194
tls-verify "/usr/local/sbin/ovpn_auth_verify tls 'OpenVPN_Cert' 1" 
lport 1194
management /var/etc/openvpn/server1/sock unix
push "dhcp-option DNS 8.8.8.8" 
push "redirect-gateway def1" 
capath /var/etc/openvpn/server1/ca
cert /var/etc/openvpn/server1/cert
key /var/etc/openvpn/server1/key
dh /etc/dh-parameters.2048
tls-auth /var/etc/openvpn/server1/tls-auth 0
data-ciphers AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305
data-ciphers-fallback AES-256-GCM
allow-compression no
persist-remote-ip
float
topology subnet
explicit-exit-notify 1
inactive 300

The sole distinction lies in whether the DCO option was activated or deactivated on the server.

23.05.1-RELEASE (amd64)
built on Wed Jun 28 03:57:27 UTC 2023
FreeBSD 14.0-CURRENT

Can confirm if DCO is not active, the widget shows the correct graphs

The same behavior on

23.09-DEVELOPMENT (amd64)
built on Fri Aug 18 06:05:19 UTC 2023
FreeBSD 14.0-ALPHA1

This bug also affects SNMP. DCO enabled, Cacti graphs stopped populating. DCO disabled, traffic graphs.

24.03-RELEASE

The issue persists in the 24.03

The traffic graph widget doesn't show traffic counts for the OpenVPN interface when DCO is enabled on the OpenVPN server.