Image file for Domoticz running on a Pi with HGI80 drivers installed

[paulockenden]

If you're struggling to download large files check the MTU on your network (clients and broadband router). That's often the problem.

[bruce_miranda]

If you're struggling to download large files check the MTU on your network (clients and broadband router). That's often the problem.

Good point. I have a BT HH5 on Infinity so the MTU is not adjustable and is fixed at 1488. I need to make sure all the clients are set to that too.
There is something definitely wrong with my network and large files. Even though I thought I had downloaded the image completely, Winzip is complaining that the file size is incorrect.

[paulockenden]

Sorry if this is granny and egg sucking but use ping with the 'do not fragment' flag, and setting the packet size to determine the best MTU for the client. Don't forget to allow for the frame overhead.

P.

[bruce_miranda]

Did that and confirmed that my MTU indeed needed to be 1488 for my NAS to connect to dropbox.com. It was previously set to 9000. Downloaded the file again via the NAS and this time the entire file came down without a problem. I've never needed to change that before and often download large files and have never had the problem. My pc wifi clients with the changed MTU setting to 1488 still gets stuck at 0.3GB for some reason.

[paulockenden]

9000 is jumbo frames. Needs the router to support them too.

As for the PC, maybe the frame overhead is higher? Especially if you have things like QoS enabled

Try

ping google.com -f -l 1488

Does it say "packets needs to be fragmented"?

If so, try setting the MTU to 1472.

Actually, before you do that try:

netsh interface ipv4 show subinterfaces

to conform that the MTU really IS set correctly, and hasn't defaulted to 1500 on the relevant interfaces.

P.

[bruce_miranda]

both my windows and mac laptops won't download the file via Chrome and Wifi. MTU has been set manually on both to 1488 which is the value set on my BT HH5. Download works fine on the Synology NAS, which is hardwired into the network. So I really don't know what is going on. All the laptops stop downloading at 0.3GB for some reason.

[paulockenden]

But like I said, the clients might need an MTU that's less than set on the router.

The ping test is the only way to set it, reliably.

P.

[bruce_miranda]

It seems like the MTU settings on the client take a while to take effect. Setting my MTU manually on my mac allowed a download via Chrome and Safari. Previously both were failing when they got to 318MB. I also confirmed by going back to the default MTU of 1500 that the downloads stopped at exactly 318MB with the default setting.
Now to working out why my windows PC still isn't taking the manual MTU setting. Maybe like everything windows, it needs a reboot for the values to take effect.

[bruce_miranda]

i realise that I am at risk of turning this into a Networking forum. But I don't seem to have any joy downloading this image directly on to my windows PC.

Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.

C:\WINDOWS\system32>netsh interface ipv4 show subinterfaces

   MTU  MediaSenseState   Bytes In  Bytes Out  Interface
------  ---------------  ---------  ---------  -------------
  1488                1    2585852     591111  Wireless Network Connection
  1500                5          0          0  Local Area Connection* 6
4294967295                1          0      28196  Loopback Pseudo-Interface 1
  1500                5          0          0  Local Area Connection* 7
  1500                5          0          0  Bluetooth Network Connection
  1488                5          0          0  Local Area Connection


C:\WINDOWS\system32>ping google.com -f -l 1488

Pinging google.com [172.217.23.46] with 1488 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.

Ping statistics for 172.217.23.46:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

C:\WINDOWS\system32>ping google.com -f -l 1460

Pinging google.com [172.217.23.46] with 1460 bytes of data:
Reply from 172.217.23.46: bytes=64 (sent 1460) time=11ms TTL=54
Reply from 172.217.23.46: bytes=64 (sent 1460) time=11ms TTL=54
Reply from 172.217.23.46: bytes=64 (sent 1460) time=12ms TTL=54
Reply from 172.217.23.46: bytes=64 (sent 1460) time=11ms TTL=54

Ping statistics for 172.217.23.46:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 11ms, Maximum = 12ms, Average = 11ms

C:\WINDOWS\system32>ping google.com -f -l 1460

Pinging google.com [216.58.208.174] with 1460 bytes of data:
Reply from 216.58.208.174: bytes=64 (sent 1460) time=60ms TTL=54
Reply from 216.58.208.174: bytes=64 (sent 1460) time=63ms TTL=54
Reply from 216.58.208.174: bytes=64 (sent 1460) time=534ms TTL=54
Reply from 216.58.208.174: bytes=64 (sent 1460) time=887ms TTL=54

Ping statistics for 216.58.208.174:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 60ms, Maximum = 887ms, Average = 386ms

C:\WINDOWS\system32>ping google.com -f -l 1461

Pinging google.com [216.58.208.174] with 1461 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.

Ping statistics for 216.58.208.174:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

This is why I set my MTU to 1488 which seems to work fine on the MBP.

[bruce_miranda]

Did you expect this error on your build?

2017-01-12 21:20:15.112 Domoticz V3.6136 (c)2012-2016 GizMoCuz
2017-01-12 21:20:15.112 Build Hash: 7affb87, Date: 2016-12-13 07:44:57
2017-01-12 21:20:15.113 System: Raspberry Pi
2017-01-12 21:20:15.113 Startup Path: /home/pi/dev-domoticz/
2017-01-12 21:20:15.687 Error: PluginSystem: Failed load 'libpython3.5.so', Python probably not installed on system.
2017-01-12 21:20:15.726 Active notification subsystems: http (1/12)
2017-01-12 21:20:15.750 WebServer(HTTP) started on address: :: with port 8080
2017-01-12 21:20:15.787 WebServer(SSL) started on address: :: with port 443
2017-01-12 21:20:15.793 Proxymanager started.
2017-01-12 21:20:15.798 Starting shared server on: :::6144
2017-01-12 21:20:15.804 TCPServer: shared server started...
2017-01-12 21:20:15.805 RxQueue: queue worker started...
2017-01-12 21:20:17.806 EventSystem: reset all events...
2017-01-12 21:20:17.811 EventSystem: reset all device statuses...
2017-01-12 21:20:17.814 EventSystem: Started

P.S. : Later found that it is a "feature" of the beta! https://www.domoticz.com/forum/viewtopic.php?t=14784