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High CPU load on enabling NAT

Posted: Sun Apr 14, 2013 11:24 am
by sorset
Hi
I'm using Packetix VPN server on ubuntu running on VPS.
I have problem , when I enable secure NAT , I see high load on cpu by vpnserver and clients speed will be decreased.
I dont use any localbridges , and server communication is directly through eth0.
whats the problem?

Re: High CPU load on enabling NAT

Posted: Tue Apr 16, 2013 2:42 am
by cedar
Please check packet log to find suspicious traffic.

The kernel-mode NAT function may cause this problem.
Please disable kernel-mode NAT in advanced virtual hub option.

Re: High CPU load on enabling NAT

Posted: Wed Apr 17, 2013 11:36 am
by sorset
Thank you ,I did but the problem not solved :(
I found in . VIrtual HUB Properties --> Edit Virtuak HUB Extended Option list --> Disable kernelmod Secure NAT , and I set it to 1 :-s
But still hsve problem, im using OpenVZ...

Re: High CPU load on enabling NAT

Posted: Wed Apr 17, 2013 5:33 pm
by sorset
In addition, when there is no VPN session over NAT there is no unusual load, but when a user connets even with low traffic I see about 100% load on cpu.

Re: High CPU load on enabling NAT

Posted: Wed Apr 17, 2013 11:57 pm
by cedar
Didn't you find some unusual traffic in packet log or system monitor?

Re: High CPU load on enabling NAT

Posted: Thu Apr 18, 2013 7:10 am
by sorset
Thank you for answering.
I'm sure that there is just one NAT user session that is my pc (windows 7 64bit) and im just connected to server's ssh for checking cpu stats. And there is no other internet or network traffic.
When I connect to vpn after a while cpu load will be at its maximum level.
I tested on ubuntu 64bit, centos 32bit and windows server 2003 32 bit
All of them have this problem with NAT.
All of the settings are default and there is no bridge. And other vpn services are disabled.
Wich logging file can be useful? I can share with you.

Re: High CPU load on enabling NAT

Posted: Fri Apr 19, 2013 1:12 am
by cedar
Please enable whole Ethernet packet log of the virtual hub temporarily.
This log may grow to huge size to upload.
Please read it yourself firstly.

Re: High CPU load on enabling NAT

Posted: Sun Apr 21, 2013 2:52 pm
by sorset
Hi
I saw that CPU load will be at 100% , even NAT user be disconnected , untill I disable secure nat or stop server!
I Think it can be softehter secureNAT bug!
So I enabled full logs, stopped the server, cleared all logs , then started server and when I see that CPU load , after about 15 seconds I stopped server.
Here is full logs... I don't see any suspicious log :(
Would you please see these logs?
thanks
http://filetrip.net/dl?wSQbpzM8cR

Re: High CPU load on enabling NAT

Posted: Mon Apr 22, 2013 1:54 am
by cedar
I don't find out suspicious log too.
SecureNAT is a most heavy function on SoftEther VPN Server.
CPU power of the VPN server host may be too low to use this function.

Try to use other NAT system such as OS embedded NAT function.

Re: High CPU load on enabling NAT

Posted: Mon Apr 22, 2013 5:41 am
by sorset
cedar wrote:
> I don't find out suspicious log too.
> SecureNAT is a most heavy function on SoftEther VPN Server.
> CPU power of the VPN server host may be too low to use this function.
>
> Try to use other NAT system such as OS embedded NAT function.

You mean it's not something like infinite loop in softether secureNAT?
OK , I'll try another one. thank you for helping.

Re: High CPU load on enabling NAT

Posted: Tue May 07, 2013 11:40 am
by Lord Farhad
Sorset I'm having the same problem, did you find any solution to this?

Re: High CPU load on enabling NAT

Posted: Tue May 07, 2013 10:41 pm
by sorset
Lord Farhad wrote:
> Sorset I'm having the same problem, did you find any solution to this?

Just try another server with stronger CPU ;)
That's already solved for me.

Re: High CPU load on enabling NAT

Posted: Wed May 08, 2013 6:24 am
by hyper
what's cpu was good for you?
and how many online clients can support?

Re: High CPU load on enabling NAT

Posted: Thu May 09, 2013 6:51 pm
by sorset
Im using on virtual machine , with 4 cores cpu.

Re: High CPU load on enabling NAT

Posted: Thu May 09, 2013 9:27 pm
by hyper
thanks for your reply

Re: High CPU load on enabling NAT

Posted: Thu Mar 19, 2015 12:03 pm
by abdullah2
cedar wrote:
> Please check packet log to find suspicious traffic.
>
> The kernel-mode NAT function may cause this problem.
> Please disable kernel-mode NAT in advanced virtual hub option.

wow thanks this method make my CPU not 99% again for now

Re: High CPU load on enabling NAT

Posted: Mon Jan 25, 2016 2:10 pm
by mbrcomp
Thank you, saved my bacon !!! Weird option !

Re: High CPU load on enabling NAT

Posted: Tue Feb 05, 2019 4:10 pm
by pribr
I solved the problem by changing the local bridge settings, in creating a tap device instead of a bridge device.