CTT Dos Attack#2

[johannwesely]

Hello, i have the following CTT Error

Any Suggestions on this ?

Greetings Johann

[kevinherron]

The DoS test cases in the CTT are broken and unreliable. Skip them for now. I've opened issues with the OPC Foundation but they are not yet fixed.

[johannwesely]

Hello,
I have an reply from Alex Allmendinger about this case "We have not been able to reproduce the problem with the DoS scripts so far. If further issues arise, the SDK developer should please get in touch with Alexander Allmendinger ([email protected]) again.

Could you explain them what is the problem here? You could refer to my name so they will know whats the point.

Greetings Johann

[kevinherron]

I found the email to Alex and revived it. I mentioned your name and linked to this discussion.

If it's the same issue in the email, the problem is that the CTT expects a server has a maximum number of secure channels allowed, and then expects certain behavior "recycling" these channels after more have been created than is allowed - but Milo has no secure channel limit, and the OPC UA spec does not require a limit nor the "recycling" behavior.

[kevinherron]

@johannwesely I would guess you're doing this already, but make sure rate limiting is disabled when you run the CTT:

Stack.ConnectionLimits.RATE_LIMIT_ENABLED = false;

[kevinherron]

@johannwesely what version of the CTT are you using?

The DoS tests seem to be passing against the demo server for me:

[kevinherron]

[johannwesely]

Hello,
I think found out why the Dos Attak#2 tests failed it was a ctt configuration error i configured max securechannles with 1 in the first place. When i configure for e.g. 10 it runs trough but i get another error instead 🙄 .

Greetings Johann

[kevinherron]

Do you have the CTT users configured?

[johannwesely]

Hello,
i had a typo in the second configured password on the server now the test runs through.

I also have a warning that the DoS attack close session takes to long im just curious why it takes so long to close the session?

Thanks Johann

[kevinherron]

I've always just assumed it has something to do with the CTT application freezing up while executing the DoS tests. You could probably look at Wireshark to see if there's really a 700+ms delay between the CloseSession request/response.

[kevinherron]

My CTT is always running in a VM which introduces a time difference >100ms in many cases. The CTT has a "Time Tolerance" setting you can change to squash the warning.

I can't see anything actually wrong.