Very slow and inconsistent internal network speed (between, VM's on the same host) for FreeBSD 11.0+ as guest on, XCP-ng/XenServer

[Christian M]

I've disabled them all on both VM's with FreeBSD 12.0-RELEASE (ifconfig xn0
-txcsum -rxcsum -lro -tso), and also tried disabling everything for the VIF
via XCP-ng earlier. It made no difference unfortunately.

Den tis 25 juni 2019 kl 14:08 skrev Eugene Grosbein <eugen at grosbein.net>:

> 25.06.2019 18:55, Christian M wrote:
>
> > Please note the
> > extremely uneven throughput for test 2 below. It's almost like the
> > throughput increased when running tcpdump simultaneously.
>
> Generally this indicates broken "hardware" offload for some features
> like txcsum/rxcsum/vlan_hwcsum/vlan_hwtagging etc.
>
> Some of them may be automatically disabled while interface is put in
> promiscuous mode
> by running tcpdump and enabled back after tcpdump terminated.
>
> You should look at "options" line in the output of ifconfig for the
> interface
> and manually disable offloads (look for ifconfig(8) manual for details).
> They retry tests without tcpdump running.
>
>