Sophos Firewall reported computer not sending heartbeat signals

Are you able to see any similar errors in the logs located at "C:\ProgramData\Sophos\Heartbeat\Logs"? 

Could the device be entering a hibernate or sleep state at the times when these events are generated?

I was on the computer and it was in standby.

I could see the Intel Networkdriver was frequently dumping something all the time during standby.

Netwtw10
7026
7026 - Dump after return from D3 after cmd

Netwtw10
7025
7025 - Dump after return from D3 before cmd

.

Probably causing network flapping which triggers Heartbeat Change.

In the heartbeat log I could see many, many events during standby mode: network has changed - firewall may disconnect

.

2022-11-16T09:21:38.596Z [ 5212: 6340] A Sending network status
2022-11-16T09:21:38.596Z [ 5212: 6340] A The network status has changed, the Firewall may disconnect.
2022-11-16T09:21:38.598Z [ 5212: 6340] A Connection closed (network error).

.

I updated (network) drivers and BIOS at first place and will monitor the situation.

Can the heartbeat module be tweaked so that it is compatible with Standby?

Everyone taks about saving energy - would be non-pc to disable standby for heartbeat to work.

The reason of those hits are quite simple: In Hibernation, the client will still send data. But the daemon of Sophos is already closed, as the sub system is already shut down. So the firewall will see the data and will react to the data as interpret them as missing heartbeat.

If you switch to hibernate, likely the endpoint cannot fetch this information not fast enough until windows will shut down the system. Therefore the missing heartbeat is generated. 

The ID above is something, where likely the client is not in hibernate, instead the daemon is shutdown for whatever reason. 

--

By adding the delay value on the firewall, you likely will decrease those alerts, as the firewall will give some time to the client ip until it will react to it. This will lead to a better reporting, as most windows clients will stop interacting with the gateway after 1-2 minutes going into hibernation. . 

it is probably something that is also in combination with the NIC Vendor. As it is standard Intel NIC on business Notebooks in our case, this should be quite common. The screenshots from event viewer above show something is happening on the NIC when it is in hibernate. This may revive heartbeat or cause some other issues with that. Anyway my opinion is that this should work unless a customer uses exotic hardware with old drivers. Not a solution is to disable hibernate or disable energy saving feature on the NIC.

If you do a tcpdump / packet capture on the IP and do the hibernation, what kind of traffic do you still see? And maybe you will find the reason by researching this traffic further. 

Hello LHerzog,

DEV has some binary ready for NC-111152, I would recommend you to open a case with Support, and you can mention about NC-111152, the case would get to GES and they can confirm is your issue matches NC-111152 and install the binary, to see if this resolves your issue.

IF you do this, share the Case ID.

Regards,

Thank you emmosophos  - is that binary for endpoint or firewall?

Hello LHerzog,

This would be for the Sophos Firewall.

Regards,

thanks! I opended case 06153996 maybe you put a hint there for the tech.

that case is like a blind flight I guess.
that's all done so far.

console> system synchronized-security delay-missing-heartbeat-detection show
285
console> system synchronized-security suppress-missing-heartbeat-to-central show
120
console>

Hello LHerzog,

Thank you for the update, I can see your case is now with GES for further investigation.

Regards,

Support tech found this which is what I already posted above: (modern) standby causes those issues.
Asking me to disable standby, which is not a desired workaround.

We've already had a case open in 2021 with SFOS 18.0.5: 04121743  Endpoints reporting "at risk"to XG firewall but Sophos Central showing no issues.

Support tech wrote there: "I believe from the logs you have provided, I do see that it went from a green connected state to a red missing heartbeat state multiple times back to back. This occurs when heartbeat traffic from the device is no longer sent to the firewall, typically after the machine enters sleep/wakes from sleep or gets disconnected.

I believe that the endpoints were having issues connecting or enters sleep/wakes from sleep very quickly that the updates were not relayed to central in time therefore it didn't show up there."

2023-03-28T13:58:53.665Z [ 5156: 5160] I Received Screen Off notification: Endpoint entering Modern Standby


2023-03-28T13:58:58.229Z [ 4800: 6088] D Failed to connect: system:10065.
2023-03-28T13:58:58.229Z [ 4800: 6088] D + Connection::OnConnectError()
2023-03-28T13:58:58.229Z [ 4800: 6088] A Connection failed.

Support tech found this which is what I already posted above: (modern) standby causes those issues.
Asking me to disable standby, which is not a desired workaround.

We've already had a case open in 2021 with SFOS 18.0.5: 04121743  Endpoints reporting "at risk"to XG firewall but Sophos Central showing no issues.

Support tech wrote there: "I believe from the logs you have provided, I do see that it went from a green connected state to a red missing heartbeat state multiple times back to back. This occurs when heartbeat traffic from the device is no longer sent to the firewall, typically after the machine enters sleep/wakes from sleep or gets disconnected.

I believe that the endpoints were having issues connecting or enters sleep/wakes from sleep very quickly that the updates were not relayed to central in time therefore it didn't show up there."

2023-03-28T13:58:53.665Z [ 5156: 5160] I Received Screen Off notification: Endpoint entering Modern Standby


2023-03-28T13:58:58.229Z [ 4800: 6088] D Failed to connect: system:10065.
2023-03-28T13:58:58.229Z [ 4800: 6088] D + Connection::OnConnectError()
2023-03-28T13:58:58.229Z [ 4800: 6088] A Connection failed.