RT-AC86U OpenVpn high cpu usage last firmware

[Enrico85]

Hi all,
I have 2 routers RT-AC86U connected to each other with a vpn site to site using openVpn (both router have server and client feature enabled)
this configuration has been working for several years, but with the firmware higher than the version 386.7_2 cpu usage grows up to 70% (100% of a single core).
restarting a router's vpn client, the problem goes away and then comes back

the command Top in terminal ssh shows:
- the OpenVpn server with 22%
- the OpenVpn client with 22%
- a third entry still related to openVpn at 15%

the problem occurs only if the routers have the same firmware version (RT-AC86U_386.9_0 or RT-AC86U_386.10_0)

I come back to the RT-AC86U_386.7_2 version and the problem does not occur.
the problem does not occur even if I update only one of the 2

RT-AC86U_386.7_2 - RT-AC86U_386.7_2 -> OK
RT-AC86U_386.7_2 - RT-AC86U_386.9_0 -> OK
RT-AC86U_386.7_2 - RT-AC86U_386.10_0 -> OK

RT-AC86U_386.9_0 - RT-AC86U_386.9_0 -> PROBLEM
RT-AC86U_386.10_0 - RT-AC86U_386.10_0 -> PROBLEM

I'm currently in this configuration:
RT-AC86U_386.7_2 - RT-AC86U_386.10_0

Thanks

 

[Darkje]

Set your router to use aes-256-gcm or aes-128-gcm for hardware encryption support.

 

[Enrico85]

I already use this settings

 

[Enrico85]

the problem is this:



thanks