Has something changed on Openvpn Server with the new release 25.12.0-rc3.
Since then I can connect to the server from client but I have no access to LAN and WAN.
Thank you
It is some time ago I used OpenVPN, I am now using WireGuard 
But some things to look at.
The VPN subnet is 192.168.9.0/24 makes sure that is unique and neither client nor routers subnet has the same or overlapping
Test from outside with your phone on cellular
Check if the LAN firewall zone has the tun+ device added
1 Like
Mediatek safexcel co-procesor is/was broken in 25.10, once you disable it ipsec or dco works at 1/3 of expected speed.
1 Like
You can follow resolution or try out proposed patches or workaround at https://github.com/openwrt/openwrt/issues/21310#issuecomment-3708334634
I recently went to battle with openVPN on build 24 with the same results, I could connect but it was a black hole with no access to LAN or WAN. I switched to Wireguard with the same results which made me think there was an issue elsewhere. I eventually got things working with some gateway tweaks but I can't recall well enough to suggest perhaps they would have also worked on openvpn.
Let's take a look at your config to see if we can figure out if there is a configuration problem or something else that might be responsible for the issues.
As an aside, I would recommend moving to WireGuard if that is an option.
Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button (red circle; this works best in the 'Markdown' composer view in the blue oval):
Remember to redact passwords, VPN keys, MAC addresses and any public IP addresses you may have:
ubus call system board
cat /etc/config/network
cat /etc/config/firewall
cat /etc/config/openvpn
(if you have an OpenVPN configuration file that is elsewhere, please post that)
I had a similar issue with a openvpn config that worked fine on 23.05.x.
With 25.12.0-rc2/3 I could connect to my router and access some/most pages/targets, but not all. In my case it was a mtu problem.
Adding "tun-mtu 1380" and "mssfix 1340" to the openvpn config solved my problem.
The numbers are probably somewhat smaller then absolutely necessary.