Degraded performance when using GRE over tinc
Loic Dachary
loic at dachary.org
Tue Apr 29 17:33:27 CEST 2014
It turns out that uploading with rsync works as fast as expected. The problem therefore seems to be : uploading works at 100Mb/s and downloading is degraded to 1Mb/s. Note that I checked that downloading on the same host without involving GRE or tinc indeed delivers 100Mb/s.
This is puzzling :-)
On 29/04/2014 16:31, Loic Dachary wrote:
> Hi,
>
> In a setup where OpenVSwitch is used with GRE tunels on top of an interface provided by tinc, I'm experiencing significant performance degradation problems (from 100Mb/s down to 1Mb/s in the worst case) and I'm not sure how to fix this. The manifestation of the problem is, from the user point of view, iperf reports ~100Mb/s and rsync reports ~1Mb/s:
>
> $ iperf -c 91.224.149.132
> ------------------------------------------------------------
> Client connecting to 91.224.149.132, TCP port 5001
> TCP window size: 23.5 KByte (default)
> ------------------------------------------------------------
> [ 3] local 10.0.2.27 port 57143 connected with 91.224.149.132 port 5001
> [ ID] Interval Transfer Bandwidth
> [ 3] 0.0-10.0 sec 99.4 MBytes 83.3 Mbits/sec
>
>
> $ rsync --progress root at 91.224.149.132:precise-server-cloudimg-amd64-disk1.img .
> precise-server-cloudimg-amd64-disk1.img
> 32112640 12% 83.44kB/s 0:45:34
>
> A tcpdump of iperf ( http://dachary.org/loic/good.cap ) shows no retransmission while a tcpdump of rsync ( http://dachary.org/loic/bad.cap ) shows a frequent "TCP Dup ACK", "TCP Retransmission", "TCP Out-Of-Order".
>
> I'm not sure why this happens, any hint would be greatly appreciated :-)
>
> Cheers
>
--
Loïc Dachary, Artisan Logiciel Libre
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 263 bytes
Desc: OpenPGP digital signature
URL: <http://www.tinc-vpn.org/pipermail/tinc/attachments/20140429/a7aad2f0/attachment.sig>
More information about the tinc
mailing list