xn ethernet issues as DOMU under NetBSD DOM0

[Sydney Meyer]

Hello, i don't know if this helps or is related to the problem, but i also had/have trouble with networking on FreeBSD DomUs, particularly with packet forwarding. For this purpose i'm running NetBSD 7.0 as a virtual router, because OpenBSD 5.9 seems to have the same problem. Perhaps this might help you narrow down the issue.

See also:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=188261
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=154428
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=197344

> On May 7, 2016, at 18:11, Stephen Jones <StephenJo at LivingComputerMuseum.org> wrote:
> 
> From: kmacybsd at gmail.com [mailto:kmacybsd at gmail.com] On Behalf Of K. Macy
>> That would explain it. If the Linux backend supports TSO, then netfront will of course advertise TSO. And >presumably there's no way to query the netback, since Xen is linux-centric. Assuming you haven't already I would >disable TSO.
> 
>> Or have you already tried that?
> 
> This morning I've tried building a kernel without the TCP_OFFLOAD option.  When booting the new system, I see this in dmesg:
> 
> xn0:  <Virtual Network Interface> at device/vif/0 on xenbusb_front0
> xn0:  Ethernet address:  00:16:3e:00:00:30
> xn0:  backend features:  feature-sg feature-gso-tcp4
> xn_txeof:  WARNING:  response is -1!
> 
> Ifconfig -v xn0 looks like:
> 
> xn0:  flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> 	options=403<RXCSUM,TXCSUM,LRO>
> 
> Pings work, ftp works (I was able to get the src.txz file off of ftp.freebsd.org to build the kernel)
> ssh does not work (handshaking fails) but I can login via telnet.  However, just about anything
> that requires lots of output gets a bit clobbered.
> 
> Are there any other kernel/sysctl parameters I should be disabling?
> 
> It is almost working, but I need help to know if this is a netfront or a netback issue.  If it is a NetBSD issue
> I'll move the discussion over to port-xen at netbsd.org
> _______________________________________________
> freebsd-xen at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-xen
> To unsubscribe, send any mail to "freebsd-xen-unsubscribe at freebsd.org"