Opened 4 years ago
#19308 new defect
Networking mode "NAT Network" shows very poor throughput
| Reported by: | tdn | Owned by: | |
|---|---|---|---|
| Component: | network/NAT | Version: | VirtualBox 6.0.16 |
| Keywords: | nat, nat network | Cc: | |
| Guest type: | Linux | Host type: | Windows |
Description
Information about my environment:
Physical Host: Windows 10 VBox version: 6.0.16
Guest VM: Debian 9 Linux, 64 bit Guest additions: 6.0.16. Networking mode: NAT Network
Use case and problem description: I have a Linux guest on Win10 host, using vbox 6.0.16 guest additions. The VM rsync files from a vboxsf shared folder to a remote host via SSH. The network is plenty fast (modern 802.11n network - not used for anything else) on which I can easily achieve > 50 MiB/s (measured by iperf) from the host to the remote server. However, when I go from guest to remote server, it maxes out at about 200kiB/s
I have checked via atop and htop that CPU is not a bottleneck on neither client nor server. And the physical network is obviously not the bottleneck... I have verified that I can both read and write files from the vboxsf share plenty fast as well.
I just tried plain NAT as networking mode and that works MUCH better. Now it is several MiBs per second. So it must be something to do with NAT network
So I guess there must be a problem in how networking is implemented in NAT Network compared to plain NAT that causes the slowdown.
