Date: Mon, 7 Apr 2014 15:50:43 +0100 From: "seanrees@gmail.com" <seanrees@gmail.com> To: Mark Felder <feld@freebsd.org> Cc: freebsd-questions@freebsd.org Subject: Re: FreeBSD 10-R, Xen 4.1 guest, pf/NAT performance question Message-ID: <CAJGy1F0V8ZL__ESO5X4rXAWb=qZ1DFfhfPbQYTYxywm1u28SSA@mail.gmail.com> In-Reply-To: <6876ba1714363dcbbdaf6b23f294fa2a@mail.feld.me> References: <CAJGy1F0aL=_U-P=wZDPc6tbKKke18PX-Ay8YUkj87=-pkXoAag@mail.gmail.com> <6876ba1714363dcbbdaf6b23f294fa2a@mail.feld.me>
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Thanks for the tip. Yes, I had already run into TSO4 causing issues with this VM, so it was switched off (ifconfig xn0 -tso4). I also set net.inet.tcp.tso=0 (was 1) and tried again - no change. :( Sean On Mon, Apr 7, 2014 at 3:10 PM, Mark Felder <feld@freebsd.org> wrote: > On 2014-04-07 07:57, seanrees@gmail.com wrote: > >> Hi there freebsd-questions, >> >> I've been batting my head against this problem for a few days now and not >> having much progress, so I'm hoping to get pointers at what to look at >> next. >> >> I've got a FreeBSD 10-R guest in Xen 4.1 (I am just a customer of the Xen >> provider; I don't run the Xen hypervisor myself). I use this instance to >> terminate a VPN, for which I also NAT VPN clients with PF. I am seeing >> unusually slow packet forwarding performance: 0.5mbit internet -> vpn >> client, 2.0 mbit vpn client -> internet. (the numbers should be closer to >> 10mbit/5mbit). >> >> This guest is a duplicate of another Xen instance I have in another data >> centre. I manage the configurations and packages centrally and aside from >> IP address differences, the machines are configured identically. The >> differences: it's 30ms closer to me and runs in Xen 3.4. I see performance >> from this machine in the 10mbps range. >> >> I've eliminated the obvious: >> - The problem VPS is fine network wise; can download tarballs from the >> Internet at 100mbps. >> - VPS -> Home is fine; can download at ~10mbps; the problem is isolated >> to forwarding Home -> VPS -> Internet and back. >> - I excluded OpenVPN as the cause by replicating the setup with ssh -w; >> same performance. >> - SSH port forwarding (ssh -L) is fast; indicating to me the issue is >> somewhere in the PF/kernel. >> - I checked TCP options by capturing traffic at varying points; these >> seem fine. I see a good deal of TCP retransmits but the window sizes stay >> the same. >> >> Any thoughts on what to check next? >> >> > Have you turned off TSO? > > ifconfig xn0 -tso > > or > > sysctl net.inet.tcp.tso=0 > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions- > unsubscribe@freebsd.org" >
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