mjhjmtu

I am using a Debian Buster VM in VirtualBox as a router for my Windows 10 notebook. [for reasons not worth mentioning here]

It has worked well for a couple of days, but yesterday and today the traffic became abnormally slow and unreliable - in my relatively stable network at home. The other devices, including the host machine were working fine. Rebooting the VM (and only the VM) fixes it for a [little] while, however the problem comes back irritatingly in a short while.

Upon close inspection, I also have errors logs on the console and in the /var/log/syslog.

My eth0 and eth1 interfaces, which are giving similar problems/errors, are virtual network interface cards.

The real equipment host is a Lenovo ThinkPad E560 Intel i7 with a Intel Dual Band Wireless-AC 3165 which is the real NIC behind the eth0 NAT.

However, eth1 is a virtual network interface of an internal network which only talks with another virtual network interface on the windows host, and is either in no way associated with real network interface cards or with external traffic. Thus the problem does not seem either to be associated only with the (external/real) network or with physical interfaces of the host machine.

The Virtual Box version is 5.2.12 r122591 (Qt5.6.2). I also installed Virtual Box tools in the VM in question.

What is happening?

The interfaces in question:

# ip a 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
 link/ether 08:00:27:f6:32:22 brd ff:ff:ff:ff:ff:ff
 inet 10.0.2.15/24 brd 10.0.2.255 scope global eth0
 valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
 link/ether 08:00:27:82:0f:24 brd ff:ff:ff:ff:ff:ff
 inet 4.1.1.1/24 brd 4.1.1.255 scope global eth1
 valid_lft forever preferred_lft forever

lspci output of the VM in question.

$ lspci
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)
00:02.0 VGA compatible controller: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter
00:03.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 02)
00:04.0 System peripheral: InnoTek Systemberatung GmbH VirtualBox Guest Service
00:06.0 USB controller: Apple Inc. KeyLargo/Intrepid USB
00:07.0 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 08)
00:08.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 02)
00:0d.0 SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 02)

Errors for eth0. Eth1 also showed the same errors.

Jun 25 08:32:22 rui kernel: [31950.194099] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:32:25 rui kernel: [31952.306456] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:32:54 rui kernel: [31981.448886] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:32:59 rui kernel: [31987.206829] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 23 20:40:58 rui systemd[1]: Started ifup for eth0.
Jun 23 20:40:58 rui kernel: [ 1.671922] e1000 0000:00:03.0 eth0: (PCI:33MHz:32-bit) 08:00:27:f6:32:22
Jun 23 20:40:58 rui kernel: [ 1.672229] e1000 0000:00:03.0 eth0: Intel(R) PRO/1000 Network Connection
Jun 23 20:40:59 rui ifup[570]: /sbin/ifup: waiting for lock on /run/network/ifstate.eth0
Jun 23 20:40:59 rui kernel: [ 4.760724] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 23 20:40:59 rui dhclient[581]: Listening on LPF/eth0/08:00:27:f6:32:22
Jun 23 20:40:59 rui sh[563]: Listening on LPF/eth0/08:00:27:f6:32:22
Jun 23 20:40:59 rui dhclient[581]: Sending on LPF/eth0/08:00:27:f6:32:22
Jun 23 20:40:59 rui sh[563]: Sending on LPF/eth0/08:00:27:f6:32:22
Jun 23 20:40:59 rui dhclient[581]: DHCPREQUEST of 10.0.2.15 on eth0 to 255.255.255.255 port 67 (xid=0x1211b42a)
Jun 23 20:40:59 rui sh[563]: DHCPREQUEST of 10.0.2.15 on eth0 to 255.255.255.255 port 67 (xid=0x1211b42a)
Jun 23 20:40:59 rui sh[563]: ifup: interface eth0 already configured
Jun 25 08:33:16 rui dhclient[644]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0xac0f1c44)
Jun 25 08:33:16 rui dhclient[644]: DHCPREQUEST of 10.0.2.15 on eth0 to 255.255.255.255 port 67 (xid=0x441c0fac)
Jun 25 08:33:45 rui kernel: [ 38.195899] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:34:23 rui kernel: [ 76.277453] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:34:37 rui kernel: [ 89.824132] NETDEV WATCHDOG: eth0 (e1000): transmit queue 0 timed out
Jun 25 08:34:37 rui kernel: [ 89.831381] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:34:39 rui kernel: [ 92.002061] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:37:59 rui kernel: [ 292.064298] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:38:01 rui kernel: [ 294.148491] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:38:12 rui kernel: [ 304.388066] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:38:37 rui kernel: [ 329.952311] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:38:39 rui kernel: [ 332.064828] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:38:56 rui kernel: [ 349.313777] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:39:01 rui kernel: [ 354.242015] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:39:03 rui kernel: [ 356.258135] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:39:04 rui kernel: [ 357.298945] e1000 0000:00:03.0 eth0: Detected Tx Unit Hang
Jun 25 08:39:05 rui kernel: [ 357.857091] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:39:07 rui kernel: [ 359.968627] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:40:45 rui kernel: [ 457.982736] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:40:47 rui kernel: [ 460.132984] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:41:28 rui kernel: [ 500.480653] e1000: eth0 NIC Link is Down
Jun 25 08:41:28 rui kernel: [ 500.480767] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:41:30 rui kernel: [ 502.755753] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:41:40 rui kernel: [ 512.834548] e1000: eth0 NIC Link is Down
Jun 25 08:41:40 rui kernel: [ 512.834570] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:41:42 rui kernel: [ 515.008848] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:41:52 rui kernel: [ 525.031738] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:41:55 rui kernel: [ 527.668391] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:42:21 rui kernel: [ 553.953056] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:42:23 rui kernel: [ 556.033233] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:42:38 rui kernel: [ 570.848721] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:42:40 rui kernel: [ 573.025803] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:42:55 rui kernel: [ 588.001188] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:42:58 rui kernel: [ 590.402069] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:43:18 rui kernel: [ 611.040602] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:43:20 rui kernel: [ 613.153379] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:43:41 rui kernel: [ 633.825059] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:43:43 rui kernel: [ 635.936611] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:43:58 rui kernel: [ 650.980297] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:44:01 rui kernel: [ 653.377622] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:44:06 rui kernel: [ 658.918888] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:44:09 rui kernel: [ 661.319139] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:44:24 rui kernel: [ 676.832703] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:44:26 rui kernel: [ 678.944975] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:44:46 rui kernel: [ 698.848483] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:44:48 rui kernel: [ 701.024837] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 08:44:52 rui kernel: [ 705.056365] e1000: eth0 NIC Link is Down
Jun 25 08:44:52 rui kernel: [ 705.056391] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 08:44:54 rui kernel: [ 707.174980] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:28:15 rui kernel: [ 3308.128693] e1000: eth0 NIC Link is Down
Jun 25 09:28:15 rui kernel: [ 3308.128863] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:28:17 rui kernel: [ 3310.241091] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:28:28 rui kernel: [ 3321.056739] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:28:30 rui kernel: [ 3323.297966] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:28:41 rui kernel: [ 3333.856657] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:28:43 rui kernel: [ 3336.001892] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:29:08 rui kernel: [ 3360.993029] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:29:10 rui kernel: [ 3363.105257] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:29:26 rui kernel: [ 3378.912149] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:29:28 rui kernel: [ 3381.007439] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:29:40 rui kernel: [ 3393.088355] e1000: eth0 NIC Link is Down
Jun 25 09:29:40 rui kernel: [ 3393.088381] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:29:42 rui kernel: [ 3395.170789] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:39:25 rui kernel: [ 3978.160481] e1000: eth0 NIC Link is Down
Jun 25 09:39:25 rui kernel: [ 3978.160521] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:39:28 rui kernel: [ 3980.353067] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:39:38 rui kernel: [ 3991.008647] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:39:40 rui kernel: [ 3993.184977] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:40:02 rui kernel: [ 4015.073022] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:40:04 rui kernel: [ 4017.249472] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:40:15 rui kernel: [ 4027.872558] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:40:17 rui kernel: [ 4029.956157] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:40:42 rui kernel: [ 4055.008653] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:40:44 rui kernel: [ 4057.091571] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:41:06 rui kernel: [ 4079.074864] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:41:08 rui kernel: [ 4081.191157] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:41:29 rui kernel: [ 4101.856291] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:41:31 rui kernel: [ 4103.968708] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:41:51 rui kernel: [ 4123.872855] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:41:53 rui kernel: [ 4125.985169] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:42:13 rui kernel: [ 4145.888157] e1000 0000:00:03.0 eth0: Reset adapter
Jun 25 09:42:15 rui kernel: [ 4147.968831] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
Jun 25 09:43:10 rui kernel: [ 4202.976829] e1000 0000:00:03.0 eth0: Reset adapter

VirtualBox VM Configuration Parameters

C:Program FilesOracleVirtualBox>VBoxManage.exe showvminfo 9806a7eb-0045-4373-bf64-1f5d6c895041
Name: Debian
Groups: /
Guest OS: Debian (64-bit)
UUID: 9806a7eb-0045-4373-bf64-1f5d6c895041
Config file: C:UsersRuiVirtualBox VMsDebianDebian.vbox
Snapshot folder: C:UsersRuiVirtualBox VMsDebianSnapshots
Log folder: C:UsersRuiVirtualBox VMsDebianLogs
Hardware UUID: 9806a7eb-0045-4373-bf64-1f5d6c895041
Memory size: 8192MB
Page Fusion: off
VRAM size: 10MB
CPU exec cap: 100%
HPET: off
Chipset: piix3
Firmware: BIOS
Number of CPUs: 2
PAE: on
Long Mode: on
Triple Fault Reset: off
APIC: on
X2APIC: on
CPUID Portability Level: 0
CPUID overrides: None
Boot menu mode: message and menu
Boot Device (1): HardDisk
Boot Device (2): DVD
Boot Device (3): Not Assigned
Boot Device (4): Not Assigned
ACPI: on
IOAPIC: on
BIOS APIC mode: APIC
Time offset: 0ms
RTC: UTC
Hardw. virt.ext: on
Nested Paging: on
Large Pages: on
VT-x VPID: on
VT-x unr. exec.: on
Paravirt. Provider: Default
Effective Paravirt. Provider: KVM
State: powered off (since 2018-06-27T15:10:06.000000000)
Monitor count: 1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address:
Teleporter Password:
Tracing Enabled: off
Allow Tracing to Access VM: off
Tracing Configuration:
Autostart Enabled: off
Autostart Delay: 0
Default Frontend:
Storage Controller Name (0): SATA
Storage Controller Type (0): IntelAhci
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0): 30
Storage Controller Port Count (0): 2
Storage Controller Bootable (0): on
Storage Controller Name (1): IDE
Storage Controller Type (1): PIIX4
Storage Controller Instance Number (1): 0
Storage Controller Max Port Count (1): 2
Storage Controller Port Count (1): 2
Storage Controller Bootable (1): on
SATA (0, 0): C:UsersRuiVirtualBox VMsDebianDebian.vmdk (UUID: 934dc586-67a5-45c9-b548-90b4f1f7bda0)
NIC 1: MAC: 080027F63222, Attachment: NAT, Cable connected: on, Trace: off (file: none), Type: 82540EM , Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 1 Settings: MTU: 0, Socket (send: 64, receive: 64), TCP Window (send:64, receive: 64)
NIC 1 Rule(0): name = Rule 1, protocol = tcp, host ip = , host port = 22, guest ip = , guest port = 22
NIC 2: MAC: 080027820F24, Attachment: Host-only Interface 'VirtualBox Host-Only Ethernet Adapter #2', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 3: disabled
NIC 4: disabled
NIC 5: disabled
NIC 6: disabled
NIC 7: disabled
NIC 8: disabled
Pointing Device: USB Tablet
Keyboard Device: PS/2 Keyboard
UART 1: disabled
UART 2: disabled
UART 3: disabled
UART 4: disabled
LPT 1: disabled
LPT 2: disabled
Audio: disabled
Audio playback: disabled
Audio capture: enabled
Clipboard Mode: Bidirectional
Drag and drop Mode: disabled
VRDE: disabled
USB: enabled
EHCI: disabled
XHCI: disabled

USB Device Filters:

<none>

Bandwidth groups: <none>

Shared folders: <none>

Capturing: not active
Capture audio: not active
Capture screens: 0
Capture file: C:UsersRuiVirtualBox VMsDebianDebian.webm
Capture dimensions: 1024x768
Capture rate: 512 kbps
Capture FPS: 25
Capture options: ac_enabled=false

Guest:

Configured memory balloon size: 0 MB

VM memory use:

$ free -m
 total used free shared buff/cache available
Mem: 7976 68 7780 2 128 7711
Swap: 2047 0 2047

VM load:

 xxxx@rui:~$ uptime
 16:28:27 up 17 min, 1 user, load average: 0,00, 0,00, 0,00

Ultimately, with luck, googling for "randomly losing connection in vbox and the errors,I stumbled upon people suggesting the default Intel NIC emulation was causing instability and performance issues. Too many random people only suggesting that after changing the default Intel virtual NIC for something else the instability went away. (sadly without any suggestion why this is happening).

So I had a look, and lo and behold, indeed in
"VM Virtualbox Manager" interface->VM name->Settings->Network->Advanced->Adapter Type" I had the default virtual NIC "Intel Pro 1000 MT Desktop (8254OEM)".

As such, I shut down the VM in question.

Knowing I had VBox tools already installed, and drawing from my experience on other virtual environment where paravirtualized NICs offer much more performance, and demands less CPU effort, I changed from the default NIC type for "Paravirtualized Network (virtio-net)" in the the two interfaces I use.

Whilst in the past VirtIO used to be known in VirtualBox for being buggy, it seems to be performing well over my tests.

The difference of speed on routing traffic has been abysmal, and the errors are completely gone.

PS. I suspect this being a vbox box bug in the emulation of a "physical" Intel NIC card, and having nothing to do with my real hardware. I actually changed first eth0, started having problems in eth1 too and then changed both. It seems the Intel VNIC emulation was giving problems in eth0 and eth1 at the same time. As I say in the question now, eth1 is in now way associated with a physical NIC.

PS2. Yes, I know paravirtualization usually gives a boost. The core question here was getting rid of serious instability.