Server is running OpenVPN 2.4.9
Client is running OpenVPN 2.5.2
The client is unable to connect to the server. I have another ovpn server on the server box and a different client box that is running OpenVPN 2.4.9 has no issues what-so-ever.
It isn't a firewall or routing issue. I am running into this after swapping hardware on the client side that WAS running OpenVPN 2.4.9 and got new equipment on client side that is running OpenVPN 2.5.2. I even went through creating a new server and client config files as well as tried running the server on the 2.5.2 side and client on the 2.4.9 side and no dice.
I assume it has something to with cipher options as there was a change between 2.4.9 and 2.5.2 but i'm not positive. Any experience in this? Here are the configs as setup right now:
SERVER running 2.4.9
SERVER
dev ovpns3
verb 1
dev-type tun
dev-node /dev/tun3
writepid /var/run/openvpn_server3.pid
#user nobody
#group nobody
script-security 3
daemon
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
proto udp4
cipher AES-256-CBC
auth SHA256
up /usr/local/sbin/ovpn-linkup
down /usr/local/sbin/ovpn-linkdown
local <public-ip-redacted>
ifconfig 10.1.101.1 10.1.101.2
lport <public-port-redacted>
management /var/etc/openvpn/server3.sock unix
max-clients 1
route 192.168.222.0 255.255.255.0
secret /var/etc/openvpn/server3.secret
compress
CLIENT running 2.5.2
CLIENT
dev ovpnc2
verb 1
dev-type tun
dev-node /dev/tun2
writepid /var/run/openvpn_client2.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
local 10.1.10.93
engine rdrand
lport 0
management /var/etc/openvpn/client2/sock unix
remote <public-ip-of-remote-redacted> <remote-port-redacted> udp4
ifconfig 10.1.101.2 10.1.101.1
route 192.168.111.0 255.255.255.0
secret /var/etc/openvpn/client2/secret
data-ciphers AES-128-GCM:AES-256-CBC
data-ciphers-fallback AES-256-CBC
allow-compression no
resolv-retry infinite
explicit-exit-notify 1