I am struggling to get my openVPN 2.5.5 working on Ubuntu 22.04.
Long story short :

• my server has been working for years (recently updated to Ubuntu 22.04)


• I have other clients connecting correctly (Windows 10, 11, Android, no other Ubuntu client)


• I have a fresh install Ubuntu 22.04 and need to connect it to my VPN as a service


• If I setup all my conf/certificates to /etc/openvpn and sudo openvpn myfile.conf, the VPN seems to initialise, but traffic is not routed to tun0, so nothing works.


• If I add routes manually, works like a charm


• If I use the same config in the gnome gui (by opening the config file directly), works also like a charm, no need to add routes later on !


• Removing pushed routes on the server just get rid of the associated error messages in the client logs, but still the 10.23.32.0/24 traffic is not routed to tun0

Tried a lot of things today and read a lot on this forum, with no luck up to now.

Any idea ?

Thanks !

RC

Config

Server.conf

#################################################

# Sample OpenVPN 2.0 config file for            #

# multi-client server.                          #

#                                               #

# This file is for the server side              #

# of a many-clients <-> one-server              #

# OpenVPN configuration.                        #

#                                               #

# OpenVPN also supports                         #

# single-machine <-> single-machine             #

# configurations (See the Examples page         #

# on the web site for more info).               #

#                                               #

# This config should work on Windows            #

# or Linux/BSD systems.  Remember on            #

# Windows to quote pathnames and use            #

# double backslashes, e.g.:                     #

# "C:Program FilesOpenVPNconfigfoo.key" #

#                                               #

# Comments are preceded with '#' or ';'         #

#################################################



# Which local IP address should OpenVPN

# listen on? (optional)

;local a.b.c.d



# Which TCP/UDP port should OpenVPN listen on?

# If you want to run multiple OpenVPN instances

# on the same machine, use a different port

# number for each one.  You will need to

# open up this port on your firewall.

port 21994



# TCP or UDP server?

;proto tcp

proto udp



# "dev tun" will create a routed IP tunnel,

# "dev tap" will create an ethernet tunnel.

# Use "dev tap0" if you are ethernet bridging

# and have precreated a tap0 virtual interface

# and bridged it with your ethernet interface.

# If you want to control access policies

# over the VPN, you must create firewall

# rules for the the TUN/TAP interface.

# On non-Windows systems, you can give

# an explicit unit number, such as tun0.

# On Windows, use "dev-node" for this.

# On most systems, the VPN will not function

# unless you partially or fully disable

# the firewall for the TUN/TAP interface.

;dev tap

dev tun



# Windows needs the TAP-Win32 adapter name

# from the Network Connections panel if you

# have more than one.  On XP SP2 or higher,

# you may need to selectively disable the

# Windows firewall for the TAP adapter.

# Non-Windows systems usually don't need this.

;dev-node MyTap



# SSL/TLS root certificate (ca), certificate

# (cert), and private key (key).  Each client

# and the server must have their own cert and

# key file.  The server and all clients will

# use the same ca file.

#

# See the "easy-rsa" directory for a series

# of scripts for generating RSA certificates

# and private keys.  Remember to use

# a unique Common Name for the server

# and each of the client certificates.

#

# Any X509 key management system can be used.

# OpenVPN can also use a PKCS #12 formatted key file

# (see "pkcs12" directive in man page).

ca ca.crt

cert server.crt

key server.key  # This file should be kept secret



# Diffie hellman parameters.

# Generate your own with:

#   openssl dhparam -out dh2048.pem 2048

;dh dh2048.pem

dh none



# Network topology

# Should be subnet (addressing via IP)

# unless Windows clients v2.0.9 and lower have to

# be supported (then net30, i.e. a /30 per client)

# Defaults to net30 (not recommended)

topology subnet



# Configure server mode and supply a VPN subnet

# for OpenVPN to draw client addresses from.

# The server will take 10.8.0.1 for itself,

# the rest will be made available to clients.

# Each client will be able to reach the server

# on 10.8.0.1. Comment this line out if you are

# ethernet bridging. See the man page for more info.

server 10.23.32.0 255.255.255.0



# Maintain a record of client <-> virtual IP address

# associations in this file.  If OpenVPN goes down or

# is restarted, reconnecting clients can be assigned

# the same virtual IP address from the pool that was

# previously assigned.

ifconfig-pool-persist /var/log/openvpn/ipp.txt



# Configure server mode for ethernet bridging.

# You must first use your OS's bridging capability

# to bridge the TAP interface with the ethernet

# NIC interface.  Then you must manually set the

# IP/netmask on the bridge interface, here we

# assume 10.8.0.4/255.255.255.0.  Finally we

# must set aside an IP range in this subnet

# (start=10.8.0.50 end=10.8.0.100) to allocate

# to connecting clients.  Leave this line commented

# out unless you are ethernet bridging.

;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100



# Configure server mode for ethernet bridging

# using a DHCP-proxy, where clients talk

# to the OpenVPN server-side DHCP server

# to receive their IP address allocation

# and DNS server addresses.  You must first use

# your OS's bridging capability to bridge the TAP

# interface with the ethernet NIC interface.

# Note: this mode only works on clients (such as

# Windows), where the client-side TAP adapter is

# bound to a DHCP client.

;server-bridge



# Push routes to the client to allow it

# to reach other private subnets behind

# the server.  Remember that these

# private subnets will also need

# to know to route the OpenVPN client

# address pool (10.8.0.0/255.255.255.0)

# back to the OpenVPN server.

;push "route 192.168.10.0 255.255.255.0"

push "route 192.168.62.0 255.255.255.0"



# To assign specific IP addresses to specific

# clients or if a connecting client has a private

# subnet behind it that should also have VPN access,

# use the subdirectory "ccd" for client-specific

# configuration files (see man page for more info).



# EXAMPLE: Suppose the client

# having the certificate common name "Thelonious"

# also has a small subnet behind his connecting

# machine, such as 192.168.40.128/255.255.255.248.

# First, uncomment out these lines:

client-config-dir ccd

;route 192.168.40.128 255.255.255.248

# Then create a file ccd/Thelonious with this line:

#   iroute 192.168.40.128 255.255.255.248

# This will allow Thelonious' private subnet to

# access the VPN.  This example will only work

# if you are routing, not bridging, i.e. you are

# using "dev tun" and "server" directives.



# EXAMPLE: Suppose you want to give

# Thelonious a fixed VPN IP address of 10.9.0.1.

# First uncomment out these lines:

;client-config-dir ccd

;route 10.9.0.0 255.255.255.252

# Then add this line to ccd/Thelonious:

#   ifconfig-push 10.9.0.1 10.9.0.2



# Suppose that you want to enable different

# firewall access policies for different groups

# of clients.  There are two methods:

# (1) Run multiple OpenVPN daemons, one for each

#     group, and firewall the TUN/TAP interface

#     for each group/daemon appropriately.

# (2) (Advanced) Create a script to dynamically

#     modify the firewall in response to access

#     from different clients.  See man

#     page for more info on learn-address script.

;learn-address ./script



# If enabled, this directive will configure

# all clients to redirect their default

# network gateway through the VPN, causing

# all IP traffic such as web browsing and

# and DNS lookups to go through the VPN

# (The OpenVPN server machine may need to NAT

# or bridge the TUN/TAP interface to the internet

# in order for this to work properly).

;push "redirect-gateway def1 bypass-dhcp"



# Certain Windows-specific network settings

# can be pushed to clients, such as DNS

# or WINS server addresses.  CAVEAT:

# http://openvpn.net/faq.html#dhcpcaveats

# The addresses below refer to the public

# DNS servers provided by opendns.com.

;push "dhcp-option DNS 208.67.222.222"

;push "dhcp-option DNS 208.67.220.220"



# Uncomment this directive to allow different

# clients to be able to "see" each other.

# By default, clients will only see the server.

# To force clients to only see the server, you

# will also need to appropriately firewall the

# server's TUN/TAP interface.

client-to-client



# Uncomment this directive if multiple clients

# might connect with the same certificate/key

# files or common names.  This is recommended

# only for testing purposes.  For production use,

# each client should have its own certificate/key

# pair.

#

# IF YOU HAVE NOT GENERATED INDIVIDUAL

# CERTIFICATE/KEY PAIRS FOR EACH CLIENT,

# EACH HAVING ITS OWN UNIQUE "COMMON NAME",

# UNCOMMENT THIS LINE OUT.

;duplicate-cn



# The keepalive directive causes ping-like

# messages to be sent back and forth over

# the link so that each side knows when

# the other side has gone down.

# Ping every 10 seconds, assume that remote

# peer is down if no ping received during

# a 120 second time period.

keepalive 10 120



# For extra security beyond that provided

# by SSL/TLS, create an "HMAC firewall"

# to help block DoS attacks and UDP port flooding.

#

# Generate with:

#   openvpn --genkey --secret ta.key

#

# The server and each client must have

# a copy of this key.

# The second parameter should be '0'

# on the server and '1' on the clients.

;tls-auth ta.key 0 # This file is secret

tls-crypt ta.key



# Select a cryptographic cipher.

# This config item must be copied to

# the client config file as well.

# Note that v2.4 client/server will automatically

# negotiate AES-256-GCM in TLS mode.

# See also the ncp-cipher option in the manpage

;cipher AES-256-CBC

cipher AES-256-GCM

auth SHA256



# Enable compression on the VPN link and push the

# option to the client (v2.4+ only, for earlier

# versions see below)

;compress lz4-v2

;push "compress lz4-v2"



# For compression compatible with older clients use comp-lzo

# If you enable it here, you must also

# enable it in the client config file.

;comp-lzo



# The maximum number of concurrently connected

# clients we want to allow.

;max-clients 100



# It's a good idea to reduce the OpenVPN

# daemon's privileges after initialization.

#

# You can uncomment this out on

# non-Windows systems.

user nobody

group nogroup



# The persist options will try to avoid

# accessing certain resources on restart

# that may no longer be accessible because

# of the privilege downgrade.

persist-key

persist-tun



# Output a short status file showing

# current connections, truncated

# and rewritten every minute.

status /var/log/openvpn/openvpn-status.log



# By default, log messages will go to the syslog (or

# on Windows, if running as a service, they will go to

# the "Program FilesOpenVPNlog" directory).

# Use log or log-append to override this default.

# "log" will truncate the log file on OpenVPN startup,

# while "log-append" will append to it.  Use one

# or the other (but not both).

;log         /var/log/openvpn/openvpn.log

;log-append  /var/log/openvpn/openvpn.log



# Set the appropriate level of log

# file verbosity.

#

# 0 is silent, except for fatal errors

# 4 is reasonable for general usage

# 5 and 6 can help to debug connection problems

# 9 is extremely verbose

verb 3



# Silence repeating messages.  At most 20

# sequential messages of the same message

# category will be output to the log.

;mute 20



# Notify the client that when the server restarts so it

# can automatically reconnect.

explicit-exit-notify 1

client_unix.conf

##############################################

# Sample client-side OpenVPN 2.0 config file #

# for connecting to multi-client server.     #

#                                            #

# This configuration can be used by multiple #

# clients, however each client should have   #

# its own cert and key files.                #

#                                            #

# On Windows, you might want to rename this  #

# file so it has a .ovpn extension           #

##############################################



# Specify that we are a client and that we

# will be pulling certain config file directives

# from the server.

client



# Use the same setting as you are using on

# the server.

# On most systems, the VPN will not function

# unless you partially or fully disable

# the firewall for the TUN/TAP interface.

;dev tap

dev tun



# Windows needs the TAP-Win32 adapter name

# from the Network Connections panel

# if you have more than one.  On XP SP2,

# you may need to disable the firewall

# for the TAP adapter.

;dev-node MyTap



# Are we connecting to a TCP or

# UDP server?  Use the same setting as

# on the server.

;proto tcp

proto udp



# The hostname/IP and port of the server.

# You can have multiple remote entries

# to load balance between the servers.

remote my_server_name_here.com 21994

;remote my-server-2 1194



# Choose a random host from the remote

# list for load-balancing.  Otherwise

# try hosts in the order specified.

;remote-random



# Keep trying indefinitely to resolve the

# host name of the OpenVPN server.  Very useful

# on machines which are not permanently connected

# to the internet such as laptops.

resolv-retry infinite



# Most clients don't need to bind to

# a specific local port number.

nobind



# Downgrade privileges after initialization (non-Windows only)

;user nobody --> will adjust when OK

;group nobody --> will adjust when OK



# Try to preserve some state across restarts.

persist-key

persist-tun



# If you are connecting through an

# HTTP proxy to reach the actual OpenVPN

# server, put the proxy server/IP and

# port number here.  See the man page

# if your proxy server requires

# authentication.

;http-proxy-retry # retry on connection failures

;http-proxy [proxy server] [proxy port #]



# Wireless networks often produce a lot

# of duplicate packets.  Set this flag

# to silence duplicate packet warnings.

;mute-replay-warnings



# SSL/TLS parms.

# See the server config file for more

# description.  It's best to use

# a separate .crt/.key file pair

# for each client.  A single ca

# file can be used for all clients.

ca ca.crt

cert my_certificate.crt

key my_key.key



# Verify server certificate by checking that the

# certificate has the correct key usage set.

# This is an important precaution to protect against

# a potential attack discussed here:

#  http://openvpn.net/howto.html#mitm

#

# To use this feature, you will need to generate

# your server certificates with the keyUsage set to

#   digitalSignature, keyEncipherment

# and the extendedKeyUsage to

#   serverAuth

# EasyRSA can do this for you.

remote-cert-tls server



# If a tls-auth key is used on the server

# then every client must also have the key.

tls-crypt ta.key



# Select a cryptographic cipher.

# If the cipher option is used on the server

# then you must also specify it here.

# Note that v2.4 client/server will automatically

# negotiate AES-256-GCM in TLS mode.

# See also the data-ciphers option in the manpage

cipher AES-256-GCM

auth SHA256



# Enable compression on the VPN link.

# Don't enable this unless it is also

# enabled in the server config file.

#comp-lzo



# Set log file verbosity.

log /etc/client/mylog.log

verb 4



# Silence repeating messages

;mute 20



key-direction 1

openvpn client log (verbose 4)

2022-08-21 20:45:01 us=612113 OpenVPN 2.5.5 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on Mar 22 2022

2022-08-21 20:45:01 us=612173 library versions: OpenSSL 3.0.2 15 Mar 2022, LZO 2.10

2022-08-21 20:45:01 us=627841 Outgoing Control Channel Encryption: Cipher 'AES-256-CTR' initialized with 256 bit key

2022-08-21 20:45:01 us=627925 Outgoing Control Channel Encryption: Using 256 bit message hash 'SHA256' for HMAC authentication

2022-08-21 20:45:01 us=627960 Incoming Control Channel Encryption: Cipher 'AES-256-CTR' initialized with 256 bit key

2022-08-21 20:45:01 us=627998 Incoming Control Channel Encryption: Using 256 bit message hash 'SHA256' for HMAC authentication

2022-08-21 20:45:01 us=628199 Control Channel MTU parms [ L:1621 D:1156 EF:94 EB:0 ET:0 EL:3 ]

2022-08-21 20:45:01 us=651688 Data Channel MTU parms [ L:1621 D:1450 EF:121 EB:406 ET:0 EL:3 ]

2022-08-21 20:45:01 us=651810 Local Options String (VER=V4): 'V4,dev-type tun,link-mtu 1549,tun-mtu 1500,proto UDPv4,keydir 1,cipher AES-256-GCM,auth [null-digest],keysize 256,key-method 2,tls-client'

2022-08-21 20:45:01 us=651833 Expected Remote Options String (VER=V4): 'V4,dev-type tun,link-mtu 1549,tun-mtu 1500,proto UDPv4,keydir 0,cipher AES-256-GCM,auth [null-digest],keysize 256,key-method 2,tls-server'

2022-08-21 20:45:01 us=651865 TCP/UDP: Preserving recently used remote address: [AF_INET]XXX.XXX.XXX.XXX:21994

2022-08-21 20:45:01 us=651918 Socket Buffers: R=[212992->212992] S=[212992->212992]

2022-08-21 20:45:01 us=651941 UDP link local: (not bound)

2022-08-21 20:45:01 us=651965 UDP link remote: [AF_INET]XXX.XXX.XXX.XXX:21994

2022-08-21 20:45:01 us=654523 TLS: Initial packet from [AF_INET]XXX.XXX.XXX.XXX:21994, sid=04ecd3ce 818d1abc

2022-08-21 20:45:01 us=666165 VERIFY OK: depth=1, CN=Easy-RSA CA

2022-08-21 20:45:01 us=666597 VERIFY KU OK

2022-08-21 20:45:01 us=666625 Validating certificate extended key usage

2022-08-21 20:45:01 us=666647 ++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication

2022-08-21 20:45:01 us=666668 VERIFY EKU OK

2022-08-21 20:45:01 us=666688 VERIFY OK: depth=0, CN=my_server

2022-08-21 20:45:01 us=684935 Control Channel: TLSv1.3, cipher TLSv1.3 TLS_AES_256_GCM_SHA384, peer certificate: 384 bit EC, curve secp384r1, signature: RSA-SHA256

2022-08-21 20:45:01 us=685040 [my_server] Peer Connection Initiated with [AF_INET]XXX.XXX.XXX.XXX:21994

2022-08-21 20:45:01 us=687068 PUSH: Received control message: 'PUSH_REPLY,route 192.168.62.0 255.255.255.0,route-gateway 10.23.32.1,topology subnet,ping 10,ping-restart 120,ifconfig 10.23.32.33 255.255.255.255,peer-id 0,cipher AES-256-GCM'

2022-08-21 20:45:01 us=687292 OPTIONS IMPORT: timers and/or timeouts modified

2022-08-21 20:45:01 us=687323 OPTIONS IMPORT: --ifconfig/up options modified

2022-08-21 20:45:01 us=687350 OPTIONS IMPORT: route options modified

2022-08-21 20:45:01 us=687377 OPTIONS IMPORT: route-related options modified

2022-08-21 20:45:01 us=687404 OPTIONS IMPORT: peer-id set

2022-08-21 20:45:01 us=687430 OPTIONS IMPORT: adjusting link_mtu to 1624

2022-08-21 20:45:01 us=687457 OPTIONS IMPORT: data channel crypto options modified

2022-08-21 20:45:01 us=687733 Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key

2022-08-21 20:45:01 us=687779 Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key

2022-08-21 20:45:01 us=687845 net_route_v4_best_gw query: dst 0.0.0.0

2022-08-21 20:45:01 us=688070 net_route_v4_best_gw result: via 192.168.62.1 dev enp2s0

2022-08-21 20:45:01 us=688163 ROUTE_GATEWAY 192.168.62.1/255.255.255.0 IFACE=enp2s0 HWADDR=70:85:c2:01:ec:6f

2022-08-21 20:45:01 us=690329 TUN/TAP device tun0 opened

2022-08-21 20:45:01 us=690421 do_ifconfig, ipv4=1, ipv6=0

2022-08-21 20:45:01 us=690511 net_iface_mtu_set: mtu 1500 for tun0

2022-08-21 20:45:01 us=690694 net_iface_up: set tun0 up

2022-08-21 20:45:01 us=691455 net_addr_v4_add: 10.23.32.33/32 dev tun0

2022-08-21 20:45:01 us=691891 net_route_v4_add: 192.168.62.0/24 via 10.23.32.1 dev [NULL] table 0 metric -1

2022-08-21 20:45:01 us=692047 sitnl_send: rtnl: generic error (-101): Network is unreachable

2022-08-21 20:45:01 us=692119 ERROR: Linux route add command failed

2022-08-21 20:45:01 us=692192 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this

2022-08-21 20:45:01 us=692255 Initialization Sequence Completed

journalctl -u NetworkManager.service

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.6931] manager: (tun0): new Tun device (/org/freedesktop/NetworkManager/Devices/4)

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7243] device (tun0): state change: unmanaged -> unavailable (reason 'connection-assumed', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7268] device (tun0): state change: unavailable -> disconnected (reason 'connection-assumed', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7284] device (tun0): Activation: starting connection 'tun0' (342de6b0-69e3-4dec-99bd-535492a1f413)

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7287] device (tun0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7292] device (tun0): state change: prepare -> config (reason 'none', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7296] device (tun0): state change: config -> ip-config (reason 'none', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7300] device (tun0): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7648] device (tun0): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7652] device (tun0): state change: secondaries -> activated (reason 'none', sys-iface-state: 'external')

août 21 20:45:01 my_client NetworkManager[643]: <info>  [1661107501.7666] device (tun0): Activation: successful, device activated.

ip link

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000

    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000

    link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff

4: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 500

    link/none

ip route (routes 10.23.32.0/24 dev tun0 missing, as well as server pushed routes)

default via 192.168.62.1 dev enp2s0 proto dhcp metric 100

169.254.0.0/16 dev enp2s0 scope link metric 1000

192.168.62.0/24 dev enp2s0 proto kernel scope link src 192.168.62.111 metric 100