Slow Download speeds for all hosts

[TJL]

Running VirtualBox 5.2.8r121009 on an Ubuntu 16.04LTS host. Download speeds from the hosts are a fraction of what they should be whereas upload speeds seem unaffected.
Machine I'm testing from is on a 100Mb wired connection. The server has 3x 1Gb links. "Download" and "Upload" are wrt the VirtualBox host/guests.

Upload and Download to/from the VirtualBox Host is confirmed at running at roughly line speed by iperf (95mbps on a 100mbps connection)
Upload to Windows/Linux VMs run at roughly equal speeds (94mbps on a 100mbps connection)
DL from Windows/Linux VMs run at a fraction of the speeds to the host (2-7mbps on the same 100mbps connection).

I've established where the issue comes from and its to do with the network configuration on the host.
The Ubuntu host has 2x 1G interfaces bonded into bond0. This LACP interface is then bridged with a 3rd 1G interface to form the bridged interface br0
The issue arises when the VMs run a bridged interface (virtio) off br0.
There is no issue when the Ubuntu host creates VLAN interfaces from br0 and the VMs use these as their bridgeadadpter.


As the upload speeds seem unaffected it seems to me that the desired configuration *could* work, I just don't know where to start

[Atari800]

Same issue here

Here are my specs:
System: H0st: PowerEdge-2950 Kernel: 4.13.0-38-generic x86_64 (64 bit gcc: 5.4.0)
Desktop: Xfce 4.12.3 (Gtk 2.24.28) Distro: Ubuntu 16.04 xenial
Machine: System: Dell product: PowerEdge 2950
Mobo: Dell model: 0CU542 v: A01
Bios: Dell v: 2.7.0 date: 10/30/2010
CPU(s): 2 Quad core Intel Xeon E5335s (-HT-MCP-SMP-) cache: 8192 KB
flags: (lm nx sse sse2 sse3 ssse3 vmx) bmips: 31920
clock speeds: max: 1995 MHz 1: 1995 MHz 2: 1995 MHz 3: 1995 MHz
4: 1995 MHz 5: 1995 MHz 6: 1995 MHz 7: 1995 MHz 8: 1995 MHz
Graphics: Card: Advanced Micro Devices] ES1000 bus-ID: 10:0d.0
Display Server: 1.19.5 drivers: ati,radeon (unloaded: fbdev,vesa)
Resolution: 1280x1024@60.02hz
GLX Renderer: llvmpipe (LLVM 5.0, 128 bits)
GLX Version: 3.0 Mesa 17.2.8 Direct Rendering: Yes
Network: Card-1: Broadcom NetXtreme II BCM5708 Gigabit Ethernet
driver: bnx2 v: 2.2.6 bus-ID: 05:00.0
IF: eno1 state: up speed: 1000 Mbps duplex: full mac: <filter>
Card-2: Broadcom NetXtreme II BCM5708 Gigabit Ethernet
driver: bnx2 v: 2.2.6 bus-ID: 09:00.0
IF: eno2 state: down mac: <filter>

Sensors: System Temperatures: cpu: 65.0C mobo: N/A
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 254 Uptime: 1:09 Memory: 6717.6/63411.7MB
Init: systemd runlevel: 5 Gcc sys: 5.4.0
Client: Shell (bash 4.3.481) inxi: 2.2.35

VirtualBox Graphical User Interface
Version 5.2.8 r121009 (Qt5.6.1)

VM1 - Windows 7 - 5 cpu's dedicated, 4 gig of ram
VM2 - Linux Mint 17.3 - 5 cpu's dedicated, 4 gig of ram

Using the HOST machine with Firefox and going to (speedof.me)
I get 230+ MB/s down and 25 MB/s up

Using Firefox in VM1 and VM2 I get about 18-20 MB/s up and about 20-25 MB/s down
I tried all of the network card options and cannot seem to get any faster

I also disabled on the host network cards thinking this may be causing the issue
sudo ethtool -K eno1 tx off sg off tso off
Actual changes:
tx-checksumming: off
tx-checksum-ipv4: off
scatter-gather: off
tx-scatter-gather: off
tcp-segmentation-offload: off
tx-tcp-segmentation: off
tx-tcp-ecn-segmentation: off
generic-segmentation-offload: off [requested on]

[TJL]

what is your network configuration with this?
is your one physical adapter on your host bridged to one virtual adapter in the VM?

Currently the only workaround I have found is to make VLAN interfaces on the host and then bridge these the virtual adapters in the VMs.
This fixes the speed issue but I'm developing a new network and there is a lot of fluidity in the configuration meaning I need to change my VM interfaces around. When the VMs handled VLAN interfaces it meant a configuration change within the VM.
The new method means every time there is an interface change the VM has to be disabled which is time consuming.

[Atari800]

what is your network configuration with this?

I tried built in physical broadcom cards and just install intel pro/1000 dual nic. The download speed of the guest is about 1/10th the speed of the host regardless how I setup the virtual nics

is your one physical adapter on your host bridged to one virtual adapter in the VM?

Yes bridged and I also tried NAT. Both experience same speed issue

Currently the only workaround I have found is to make VLAN interfaces on the host and then bridge these the virtual adapters in the VMs.
This fixes the speed issue but I'm developing a new network and there is a lot of fluidity in the configuration meaning I need to change my VM interfaces around. When the VMs handled VLAN interfaces it meant a configuration change within the VM.
The new method means every time there is an interface change the VM has to be disabled which is time consuming.

I'll try making a vlan on host and see what happens
Thanks for the response

[Peter Kuykendall]

I'm having a similar problem. I have tcpdump captures and screen shots. Somehow the networking is screwed up under Virtualbox in certain conditions, but I don't yet know why, nor how to fix it. Details in a post here https://sourceforge.net/p/drbl/discussi ... 4a9a/#0fa6.