> On 25 Oct 2015, at 18:47, James Lodge <ja...@lodge.me.uk> wrote: > >> On 25 Oct 2015, at 17:46, James Lodge <ja...@lodge.me.uk> wrote: >> I currently have a FreeBSD 10.1 host running on Digital Ocean. I have >> multiple jails and I'm not using vimage. >> >> >> I'm using PF on the host to NAT traffic from said jails and all is working >> as expected. I have a jail running OpenVPN and clients can connect and >> traffic is routed to the Internet down the tunnel via PF/NAT. The issue I'm >> seeing is download speeds to the client from the Internet on the external >> side on PF. Upload always seem reasonable, but download is always woeful. >> I'm using a Windows machine as the client if that make any odds. >> >> Yeah, there’s an issue with checksums and pf/Xen. >> Disabling TSO should work for you (sudo sysctl net.inet.tcp.tso=0), and the >> problem should be completely fixed in the >next release (10.3 or 11.0) >> >> Regards, >> Kristof > > > Thanks Kristof for the quick reply, > > I was hoping it would be that simple, but Digital Ocean use KVM (from what I > know) as their hypervisor so disabling TSO and LRO seems to have no noticed > increase in performance. > >Can you run a tcpdump while you’re seeing the problem? >The issue I know about is related to the TCP checksum, so I’d expect to see >many invalid checksums. > >Regards, >Kristof
There are discussions/threads regarding KVM/TSO with the same symptoms, but I would expect to see the same poor performance through PF be it local or remotely via OpenVPN, but I don't. Local I see perfect performance in and out from the host and jails. Running wireshark locally on the windows client and downloading from the Internet via PF, I see a lot of retransmissions and duplicate ACKs. 28 0.824146000 80.249.99.148 10.8.0.10 TCP 1422 [TCP Retransmission] 80→57292 [ACK] Seq=9577 Ack=1 Win=14 Len=1368 33 0.872164000 10.8.0.10 80.249.99.148 TCP 66 [TCP Dup ACK 29#1] 57292→80 [ACK] Seq=1 Ack=13681 Win=256 Len=0 SLE=15049 SRE=16417 I don't see any retransmissions or duplicate ACKs when downloading from the web server jail via its private IP down the tunnel. if I run tcpdump i tun0 -n at the same time as seen the retransmissions and duplicate ACKS I get..... 20:26:58.567017 IP 10.8.0.10.60339 > 80.249.99.148.80: Flags [.], ack 437760, win 256, options [nop,nop,sack 1 {440496:443232}], length 0 20:26:58.568680 IP 80.249.99.148.80 > 10.8.0.10.60339: Flags [.], seq 437760:439128, ack 1, win 14, length 1368 20:26:58.580530 IP 10.8.0.10.60339 > 80.249.99.148.80: Flags [.], ack 439128, win 256, options [nop,nop,sack 1 {440496:443232}], length 0 20:26:58.585141 IP 80.249.99.148.80 > 10.8.0.10.60339: Flags [.], seq 443232:444600, ack 1, win 14, length 1368 20:26:58.596466 IP 10.8.0.10.60339 > 80.249.99.148.80: Flags [.], ack 439128, win 256, options [nop,nop,sack 1 {440496:444600}], length 0 Regards James _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"