[FreeBSD 8.2 amd64 XENHVM] DomU terrible network performance trought NAT

[Tobias P. Santos]

Try this:

ifconfig xn1 -txcsum

Best regards,
Tobias.


Laurent Cligny wrote:
> Hello all,
>
> I want to setup a FreeBSD DomU VM as a network NAT gateway in order to
> provide Internet access to other FreeBSD and Linux DomU VMs.
> My Dom0 is Xen Cloud Platform 1.0 on a Dell Poweredge 210 with 8 cores,
> 16GiB RAM and one NIC.
>
> All FreeBSD VM are 8.2 amd64 with XENHVM kernel anf the Linux VM is a
> Paravirtualized Debian amd64.
>
> The NAT gateway is a two-NIC box, with one (xn0) configured with a
> public Internet address and the other (xn1) configured with a class A
> private address (10.0.0.254).
> The Internet traffic is very good from my FreeBSD NAT gateway to the
> Internet (~ 50MiB/s) and also between other VMs on the private network
> (~ 70MiB/s trough scp) after applying the patch here
> (http://www.mail-archive.com/freebsd-xen@freebsd.org/msg00855.html)
> fixing the "too many frags" problem.
>
> Here is a schema of my setup with the observed net speed on it:
>
> ----------         ---------------         ----------------------
> |Internet|---xn0---|FBSD DomU NAT|---xn1---|FBSD and Linux DomUs|
> ----------         ---------------         ----------------------
>           <------->               <------->
>            50MiB/s                 70MiB/s
>
>           <------------------------------->
>            0KiB/s <network speed< 5 KiB/s
>
> [...]