Networking under Xen

[Mark Felder]

On Tue, Jul 14, 2015, at 07:36, Sydney Meyer wrote:
> Hello everybody,
> 
> i have noticed some odd behaviour with networking under Xen with FreeBSD
> 10 as a DomU.
> 
> - IPv6 (TCP) bandwith drops from ~10 Gbit/s IPv4 to around 3 Gbit/s IPv6.
> (measured with iperf)
> 

What is the "before" and "after" here? When is FreeBSD successfully
doing 10Gbit/s and when isn't it? Is pf enabled? Are you scrubbing?

> - Dropped/Stalled Connections with TCP Segmentation Offload and pf
> enabled.
> 

TSO is a known issue. I've been turning it off for years to get FreeBSD
to play nice on Xen.

> - IPSEC-enabled Kernel TCP Performance drops from ~10 Gbit/s to ~200
> Mbit/s (iperf).
> 

Are you saying FreeBSD non-IPSEC kernel can do 10Gbit/s TCP performance,
but IPSEC kernel immediately drops it to 200Mbit/s?