SoftEther SSTP spontaneous consumption of 100% CPU

[Anna_K]

I am using:
debian 12
SoftEther VPN Server (Ver 4.42, Build 9798, rtm)

config SoftEther VPN:
> SecureNatEnable
> SstpEnable yes
> KeepDisable
> SetEnumDeny
> ListenerCreate 43001
> ListenerDelete 5555
> ListenerDelete 443
> DhcpSet /START:192.168.30.12 /END:192.168.30.200 /MASK:255.255.255.0 /EXPIRE:7200 /GW:192.168.30.1 /DNS:1.0.0.1 /DNS2:1.1.1.1 /DOMAIN:none /LOG:yes /PUSHROUTE:none

There are only 3 users

the program spontaneously consumes 100% of the CPU at different intervals. CPU consumption lasts for 20-30 minutes and then stops
I checked the traffic movement at this point in time, no, I even turned off all clients for CPU consumption continued. ports are not strange, it's not hackers who will hack them. everything is fine in the logs and there are no problems.

Where is the problem why is the program consuming CPU?

[solo]

Try viewtopic.php?f=7&t=68546#p100051
If unresolved, report it on Github.

[Anna_K]

changing the parameter DisableIpRawModeSecureNAT did not help.
I think you need to delete the old 4th version and install the new 5th version.
I'll write later when I compile a new version and observe for a few days

[Anna_K]

Upgrading from version 4 to version 5 does not help. Both versions have the problem.
SoftEther VPN Server 4.42, Build 9798
SoftEther VPN Server 5.02.5187

There is a problem in the source code of both versions, it needs to be fixed. How can I help solve the problem?

[solo]

If unresolved, report it on Github.

https://github.com/SoftEtherVPN/SoftEtherVPN/issues

[Anna_K]

there is already a similar problem on the github website https://github.com/SoftEtherVPN/SoftEth ... ssues/2000
the problem arose back in May of this year (5 months ago).

and the 5th version is being discussed on the github website. you are discussing the 4th version. I am ready to help both projects.

[solo]

Very well, please disable SecureNAT and replicate its functionality with dnsmasq and iptables.

?

[Anna_K]

using SecureNat for me is more of an advantage, I really don't want to turn off this function. and in addition I need help and instructions on how to replace SecureNat through the built-in dnsmasq and iptables in debian 12.

[solo]

For a test simply turn SecureNAT off, restart the service, and observe it just like you did earlier with no VPN traffic...

"I even turned off all clients for CPU consumption continued.

[Anna_K]

disabling SecureNAT will disable all clients completely, no user will be able to connect. You want to test a simply working server without clients and without traffic. Do I understand you correctly?

It's hard for me to do this. You have to wait until the weekend. You can't just turn off all clients on weekdays. Please wait until the end of the week.

[Anna_K]

I approximately understood where the problem was. At the beginning of viewing sites through this VPN and with a large load, many connections are opened and it seems to be buggy there. The test was held on Mikrotik routers (there were 4 different versions of routers). If you look at the site simply and slowly, everything is good, but with the fast leaflet of the Facebook tape, for example, a noble load on a router occurs up to 100% within 30 minutes. The load continues to remain 100% even after the client is disconnected from VPN

[solo]

Which means that the no-SecureNAT test must involve active connections. Disable SecureNAT and bridge the hub to a soft tap search.php?keywords=soft+tap

At this point SoftEther's role ends and common Linux setup starts. We don't offer OS guides nor support its issues, but the setup had been extensively discussed before:
search.php?keywords=iptables
search.php?keywords=dnsmasq

BTW "dnsmasq vs SecureNAT" viewtopic.php?f=7&t=67986&p=97671#p97671
It's better anyway.