LanSchool 8.0 - 'Student machine entered standby mode' / no viewing or remote control

[gwendes]

Upgrade from v7.7 with teacher's stations as the server to v8.0 with a new LCS.

 

LCS sees the teacher and student computers - channels and LCS settings deployed with ADMs

 

After a couple of restarts all computers in the rooms are connected but a lot are losing connection and entering standby mode, this is happening at random. For example a teacher can be viewing and remote controlling a student without any problems and then the console will report that the student has gone into standby mode when they clearly haven't! Any ideas?

 

The old 7.7 worked flawlessly, now my ticketing system is filling up with reports of LanSchool problems :/

 

[LanSchoolUK_Adam]

Hi Giles,

 

Sorry to hear about the issues you've been experiencing with LanSchool since moving to the client-server architecture.

 

LanSchool uses the following ports for p2p outbound comms (Teacher-to-Student)

 

2426 - Discovery Packet

796 - Data Request

1053 - Status Packet

 

When routing it via the LCS, the request goes out (Teacher-to-LCS) on the above ports, and the LCS forwards them to the student on port 8080.

 

In both cases, Student-to-Teacher responses are done on a dynamic port number between 48000-62000 (with the LCS relaying the request).

 

If the machines are randomly flicking between Active and Standby, it would indicate that the status packet is being periodically dropped; the request is going out but not coming back. As the Teacher doesn't receive a response, it assumes the Student is in Standby.

 

To troubleshoot this, I would recommend isolating the issue by moving one affected classroom back to p2p mode (you can use the Tech Console to flip groups of PC's between p2p and client-server) and see if the issue persists.

 

If it doesn't, convert the room back to client-server through the Tech Console and run a WireShark trace on the LCS itself to see if it detects any packet loss.

[gwendes]

This is happening in every single classroom. We currently have 12 IT suites configured.

 

If I change the settings with the TechConsole I will need to remove the Group Policy that is applying first and gpupdate all the computers?

[LanSchoolUK_Adam]

If your GPO's run on machine bootup then you can test it by booting up all the machines in a suite (if they're not already on), authenticating them if needed, and then doing what you need to do in the Tech Console. There is no machine reboot requirement for this; you can do it all in one session;

 

Manage > Update LanSchool > Disable LCS (Teacher and Students)

 

 

Replicate the issue

 

Manage > Update LanSchool > Enable LCS and enter server IP

 

If your GPO's run on user login, it may be best to temporarily disable them for this room while you troubleshoot, so that they don't revert the settings back.

[gwendes]

If this works are you suggesting that we move back to the old configuration? This change was made on the advice of your colleague.

 

Running a WireShark from the LCS, what do you suggest we look for? I have it installed.

[gwendes]

Slight side-note, is it possible to see the students mouse pointer? One of my colleagues has raised that this feature now seems to be missing?

[LanSchoolUK_Adam]

p2p is great for smaller, flatter networks. For anything larger, especially where VLAN's are concerned, we recommend the LCS.

 

Technically you can port-forward your p2p broadcast traffic across VLAN's, but that's why the LCS was created - so you don't have to de-segregate your segregated network

 

Wireshark will show you dropped/broken/corrupted packets (marked in black) if you use the filter tcp.analysis.lost_segment but this might end up being a rabbit hole (as you would have to run traces on the Teacher, the LCS and the Student, and then compare them).

 

There is a Debug Trace/Logging available on the LCS itself - a member of our IT support team will be in contact with you to set this up and grab the capture logs.

 

[gwendes]

p2p is great for smaller, flatter networks. For anything larger, especially where VLAN's are concerned, we recommend the LCS.

 

Technically you can port-forward your p2p broadcast traffic across VLAN's, but that's why the LCS was created - so you don't have to de-segregate your segregated network

 

Wireshark will show you dropped/broken/corrupted packets (marked in black) if you use the filter tcp.analysis.lost_segment but this might end up being a rabbit hole (as you would have to run traces on the Teacher, the LCS and the Student, and then compare them).

 

There is a Debug Trace/Logging available on the LCS itself - a member of our IT support team will be in contact with you to set this up and grab the capture logs.

 

[ATTACH=CONFIG]45517[/ATTACH]

 

We have a large network with three data VLANs. It would be good to speak to someone, can you PM me a DDI?

[LanSchoolUK_Adam]

Done

[gwendes]

Done

 

Thanks, spoken with your technical support and they're escalating to Lenovo.

 

Hopefully we can get to the bottom of this one soon!

[stevewill6]

Hi, Did you manage to get to the bottom of this? I am currently experiencing the same issues.

 

Thanks

[LanSchoolUK_Adam]

Hi all,

 

With multiple customers reporting the same issue and the same fix resolving it, this has been logged as a bug to be addressed in the next build release.

 

The issue seems to occur only on the 'new' type of screen cast used in LanSchool 8 for both Show and Control, and is present in the Teacher Console but not the Tech Console.

 

You can resolve this on the Teacher machines by implementing the below registry keys (ideally on your staff machine GPO);

 

 

32-bit Teachers:

HKEY_LOCAL_MACHINE\Software\LanSchool\

Values (DWORD 32):

 

UseLegacyRemoteControl = 1

UseLegacyShow = 1

 

 

64-bit Teachers:

HKEY_LOCAL_MACHINE\Software\Wow6432Node\LanSchool\

Values (DWORD 32):

 

UseLegacyRemoteControl = 1

UseLegacyShow = 1

 

 

 

Thanks to everyone who helped us replicate/isolate the issue and confirmed the fix. I will update this thread once the new build is made available.

- Adam

[PurpleTentacle]

We are (hopefully were) getting an issue after blanking screens too.

 

I'll update my ticket with Lenovo to let them know I'm implementing this (potential) fix.