[Bug]: Slow transfer speed from VM when going through a router with certain NIC types

[thedisbo1125]

Version

7.2.14

Host OS Type

Linux

Host OS name + version

Ubuntu 22.04.5 LTS (Jammy Jellyfish)

Host Architecture

x86

Guest OS Type

Linux

Guest Architecture

x86

Guest OS name + version

Linux Mint Mate 22

Component

Network

What happened?

When transferring files from the VM to another machine and it crosses a router (external to the host machine), speed is really slow when compared to files to the VM. I found both NIC types 82540EM and 82545EM are affected. Problem first appeared in VirtualBox 7.0.0. I tested version 6.1.50 and this was not an issue.

Doing a search for "bridged" shows several other tickets for similar issues.

Issue not just sftp, really slow when moving files to samba share from VM

How can we reproduce this?

• install Ubuntu 22 on PC with two NICs for host.
• nstall openssh-server
• assign IP addresses to the two NICs on separate subnets.
• connect the NICs to a switch that can perform intervlan routing.
• configure switch to route between the different subnets.
• install VirtualBox 7.0.0 or later.
  -create VM with bridged adapter on one subnet.
• boot VM with Mint Mate 22 (what I had available with live trial)
• assign IP address to VM
• sftp to host IP on 2nd subnet and download, then upload any decently large file, upload back to host takes way longer.

attached doc has some pics of transfer speeds.

testbox-for-slow.odt

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.

[thedisbo1125]

That command Aleksey Ilyushin suggested in an email (sudo ethtool -K <interface_name> tso off) fixed the issue, though I don't think it should be the final solution. There are several open issues (besides mine) for this, and I also found a couple posts on other IT forums about it. Those are what led me to testing different NIC types.

Also, I traced the issue to Commit 30b46e8 on May 9, 2022, specifically adding the defined "VBOXNETFLT_WITH_GSO_XMIT_HOST" to VBoxNetFlt-linux.c‎. Not sure removing it would be the correct fix since it doesn’t appear to affect every VM NIC type.

I’m going to compile the latest 7.2 code with it, test all the NICs that can be set with GUI frontend, then without it and do the same test.

I’ll post those results in the issue I opened later this weekend.

Rich

[thedisbo1125]

Attached file has pics of the transfer rates for latest 7.2 code with and without the define "VBOXNETFLT_WITH_GSO_XMIT_HOST".

test-v7.2.odt