[cifs-protocol] MS-SWM Q10 - 3.1.6.1 Server Application Notifies of an Interface Being > Enabled or Disabled - TrackingID#2401040040013236

[Jeff McCashland (He/him)]

[Hung-Chun and Kristian to BCC]

Hi Stefan, 

I will dig into this and let you know what I find. 

Best regards,
Jeff McCashland (He/him) | Senior Escalation Engineer | Microsoft Protocol Open Specifications Team
Phone: +1 (425) 703-8300 x38300 | Hours: 9am-5pm | Time zone: (UTC-08:00) Pacific Time (US and Canada)
Local country phone number found here: http://support.microsoft.com/globalenglish | Extension 1138300

-----Original Message-----
From: Hung-Chun Yu <HungChun.Yu at microsoft.com> 
Sent: Thursday, January 4, 2024 1:59 PM
To: metze <metze at samba.org>
Cc: cifs-protocol at lists.samba.org; Kristian Smith <Kristian.Smith at microsoft.com>; Hung-Chun Yu <HungChun.Yu at microsoft.com>; Microsoft Support <supportmail at microsoft.com>
Subject: MS-SWM Q10 - 3.1.6.1 Server Application Notifies of an Interface Being > Enabled or Disabled - TrackingID#2401040040013236

[BCC dochelp]

Hi Stefan

Since Kristian will be out of office until after Jan 23, 2024. We went ahead and create SR Case - TrackingID#2401040040013236. Do leave this tag in the Subject line for future reference and tracking.

One of our engineers will contact you shortly.

Hung-Chun Yu
hunyu at microsoft.com
Protocol Support

-----Original Message-----
From: Stefan Metzmacher <metze at samba.org>
Sent: Thursday, January 4, 2024 8:52 AM
To: Kristian Smith <Kristian.Smith at microsoft.com>; Interoperability Documentation Help <dochelp at microsoft.com>
Cc: cifs-protocol at lists.samba.org
Subject: Re: [EXTERNAL] Trying to let a Windows client use MS-SWN against a samba cluster

[You don't often get email from metze at samba.org. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]

Am 11.12.23 um 22:15 schrieb Kristian Smith:
> Hi Metze,
>
> I'm reaching out with regard to question 10 from your mail below.
>
> ----------------------------------------------------------------------
> -----------------------------------
> Question 10:
> MS-SWM 3.1.6.1 Server Application Notifies of an Interface Being 
> Enabled or Disabled
>
>     The calling application provides the interface group name, IPv4 and/or IPv6
>     addresses, and state.
>     ...
>     Then for each entry in the WitnessRegistrationList where
>     WitnessRegistration.NetworkName
>     matches the application-provided interface group name ...
>
> This seems to indicate that there's actually just a single 
> InterfaceGroupName matching the single NetworkName.
> ----------------------------------------------------------------------
> -----------------------------------
>
> WitnessRegistration.NetworkName is the NetName provided by the client when registering.
> InterfaceGroupName is provided by the Server Cluster application.

That's also my understanding.

But on a windows 2012 cluster I saw that the interfaceGroupNames in the GetInterfaceList() response are the per node netbios names (something like node0, node1, node2) that hold the related ip address.

But the NetworkName in th Register[Ex]() request from the client gets the sofs cluster name, something like "sofs-cluster" or "sofs-cluster.example.com" (which has to match ServerGlobalName (See Question 11).

With that the statement:

   Then for each entry in the WitnessRegistrationList where WitnessRegistration.NetworkName
   matches the application-provided interface group name ...

would never be true and no registration in the list will ever get any notification...
So it seems to be a documentation bug.

In my code I'm comparing WitnessRegistration.IpAddress being equal to the ip address of the changed interface.

> If there are no current registered witnesses (clients), the 
> Interface.InterfaceGroupName would still exist, but there would be no WitnessRegistration.NetworkName This check (referenced in your question) compares the server-application-provided InterfaceGroupName (the one that underwent a state change) to those in the list of registered witnesses. This ensures that the client receives a message about the state change.

It would mean on windows that it compares "node0" to match "sofs-cluster.example.com", which can't work.

> Please let me know if there are lingering concerns with Question 10 and I'd be happy to dig back in.

Please do :-)

Thanks!
metze