Intermittent TCP connect issues when using tinc 1.0.23 and IPv6

[tomp at tomp.co.uk]

Hi Guus

Sorry for replying to the digest in my last E-mail.

Now that debugging is turned on properly, I am seeing some interesting 
lines:

2013-11-28 14:48:48 tinc.dcvpn[31620]: Got type 2 MTU probe reply 1431 
from rps (2001:1b40:5000:9::2 port 655)
2013-11-28 14:48:48 tinc.dcvpn[31620]: Got type 2 MTU probe reply 1431 
from rps (2001:1b40:5000:9::2 port 655)
2013-11-28 14:48:48 tinc.dcvpn[31620]: Got type 2 MTU probe reply 1431 
from rps (2001:1b40:5000:9::2 port 655)
2013-11-28 14:48:48 tinc.dcvpn[31620]: rps (2001:1b40:5000:9::2 port 
655) RTT 0.49 ms, burst bandwidth 51.684 Mbit/s, rx packet loss 100.00 %

Specifically the bit about 100% packet loss.

It was shortly after following by:

2013-11-28 14:51:01 tinc.dcvpn[31620]: Got REQ_KEY from rps 
(2001:1b40:5000:9::2 port 55170): 15 rps rsukmhb 21 AA...

I got a REQ_KEY request 12 times in 1s from rps.

Tom

On 2013-11-28 14:28, tomp at tomp.co.uk wrote:
> I can confirm this issue is also occurring when using tinc 1.1pre9
> with elliptic encryption.
> 
> On 2013-11-28 12:12, tomp at tomp.co.uk wrote:
>> Here's some more info, as a timeout just occurred using rsync from
>> rsukmhb to rps sites:
>> Nov 28 11:59:01 rsuk-mhb-pubweb101 php: ict-pubweb [SyncSites]
>> (21294) Info: Plugin started
>> Nov 28 11:59:01 rsuk-mhb-pubweb101 php: ict-pubweb [SyncSites]
>> (21294) Info: Last sync build time: 2013-11-27 09:50:40
>> Nov 28 11:59:16 rsuk-mhb-pubweb101 php: ict-pubweb [SyncSites]
>> (21294) Error: Rsync failed: rsync error: timeout waiting for daemon
>> connection (code 35) at socket.c(279) [receiver=3.0.6]
>> Nov 28 11:59:16 rsuk-mhb-pubweb101 php: ict-pubweb [SyncSites]
>> (21294) Info: Plugin stopped
>> Rsync is configured with a connection timeout of 15s, so the
>> connection was started at 11:59:01 and timed out at 11:59:16.
>> At the same time our import cron process ran from rps to the same
>> server that was running the rsync client:
>> Nov 28 11:59:01 rsuk-mhb-pubweb101 httpd: pubweb.infinity.local
>> rsuk-mhb-pubweb101.ictnw.net 2001:1b40:5600:1::76 - ict-pubweb
>> [28/Nov/2013:11:59:01 +0000] "GET
>> /v1/cmsEvents?limit=1000&sort%5B0%5D=rowId-asc&filter%5B0%5D=siteId-in-value-2&filter%5B1%5D=rowId-gt-value-933&filter%5B2%5D=eventType-eq-value-lead
>> HTTP/1.0" 200 - "-" "Icc HTTP Client"
>> I am running tinc with debug mode 5 on both firewalls so here is a
>> sample of the logs from both at that time:
>> rsukmhb site (where rsync client is):
>> -----------------------------------------
>> [thomas.parrott at rsuk-mhb-fw01 ~]$ grep '11:59:' /var/log/messages
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 224 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 88
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 87
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 108 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 82
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:01 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 136 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 82
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 79
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 89
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 89
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 80
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 79
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:02 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:03 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 139 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:04 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:04 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:08 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:08 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:10 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 224 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:11 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:12 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:13 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:14 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:16 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:16 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:21 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:21 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:21 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:21 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 224 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:21 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:21 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:29 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:29 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:29 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:29 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 224 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:29 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:29 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:34 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 129 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:39 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:39 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:39 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:39 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 224 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:39 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:39 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:42 rsuk-mhb-fw01 tinc.dcvpn[24911]: Got MTU probe length
>> 1443 from rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:42 rsuk-mhb-fw01 tinc.dcvpn[24911]: Got MTU probe length
>> 1443 from rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:42 rsuk-mhb-fw01 tinc.dcvpn[24911]: Got MTU probe length
>> 1443 from rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending MTU probe
>> length 1451 to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending MTU probe
>> length 1443 to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending MTU probe
>> length 1443 to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending MTU probe
>> length 1443 to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Got MTU probe length
>> 1443 from rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Got MTU probe length
>> 1443 from rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Got MTU probe length
>> 1443 from rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:43 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:44 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:45 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:46 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:47 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 118 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:49 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:49 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:49 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:49 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 224 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:49 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:49 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Clamping MSS of
>> packet from rsukmhb to rps to 1369
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 86
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 112 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of
>> 106 bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 89
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> Nov 28 11:59:55 rsuk-mhb-fw01 tinc.dcvpn[24911]: Sending packet of 74
>> bytes to rps (2001:1b40:5000:9::2 port 655)
>> rps site (where rsync server is):
>> -----------------------------------------
>> [thomas.parrott at rps-fw03 ~]$ grep '11:59:' /var/log/messages
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 433
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 88
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 115
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:01 rps-fw03 tinc.dcvpn[17321]: Sending packet of 75
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 78
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 78
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1417
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1443
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 1035
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 89
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 89
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 79
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 98
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:02 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:03 rps-fw03 tinc.dcvpn[17321]: Sending packet of 107
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:10 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Sending packet of 433
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:11 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:12 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:13 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:14 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:21 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:21 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:21 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:21 rps-fw03 tinc.dcvpn[17321]: Sending packet of 433
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:21 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:21 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:29 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:29 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:29 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:29 rps-fw03 tinc.dcvpn[17321]: Sending packet of 433
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:29 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:29 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:34 rps-fw03 tinc.dcvpn[17321]: Sending packet of 122
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:39 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:39 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:39 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:39 rps-fw03 tinc.dcvpn[17321]: Sending packet of 433
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:39 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:39 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Sending MTU probe length
>> 1451 to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Sending MTU probe length
>> 1443 to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Sending MTU probe length
>> 1443 to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Sending MTU probe length
>> 1443 to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Got MTU probe length 1443
>> from rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Got MTU probe length 1443
>> from rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:42 rps-fw03 tinc.dcvpn[17321]: Got MTU probe length 1443
>> from rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:43 rps-fw03 tinc.dcvpn[17321]: Got MTU probe length 1443
>> from rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:43 rps-fw03 tinc.dcvpn[17321]: Got MTU probe length 1443
>> from rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:43 rps-fw03 tinc.dcvpn[17321]: Got MTU probe length 1443
>> from rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:43 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:44 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:45 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:46 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:47 rps-fw03 tinc.dcvpn[17321]: Sending packet of 118
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:49 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:49 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:49 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:49 rps-fw03 tinc.dcvpn[17321]: Sending packet of 433
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:49 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:49 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Clamping MSS of packet
>> from rps to rsukmhb to 1369
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 86
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 105
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 80
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Nov 28 11:59:55 rps-fw03 tinc.dcvpn[17321]: Sending packet of 74
>> bytes to rsukmhb (2001:1b40:5000:19::2 port 655)
>> Neither firewalls are heaving loaded.
>> Thanks
>> Tom
>> 
>> On 2013-11-28 11:49, tomp at Tomp.co.uk wrote:
>>> Hi,
>>> I am using tinc 1.0.23 in router mode and am having trouble with
>>> intermittent TCP connect timeouts that do not occur when routing the
>>> TCP over the internet directly.
>>> I am using a pure IPv6 setup (i.e direct IPv6 connections, and
>>> tunneled IPv6 subnets).
>>> My configs are as follows:
>>> Site 1:
>>> -----------------------
>>> tinc.conf:
>>> Name = rsukmhb
>>> AddressFamily = ipv6
>>> BindToAddress = 2001:1b40:5000:19::2
>>> ConnectTo = rps
>>> IffOneQueue = yes
>>> tinc-up:
>>> #!/bin/sh
>>> logger -t tinc Bringing up interface $INTERFACE
>>> ip -6 link set "$INTERFACE" up
>>> ip -6 link set "$INTERFACE" txqueuelen 10
>>> ip -6 addr add fdd1:c52a:3c24:3384::2/64 dev "$INTERFACE"
>>> subnet-up:
>>> #!/bin/sh
>>> [ -z "$NAME" ] && exit 0
>>> [ "$NAME" = "$NODE" ] && exit 0
>>> logger -t tinc Adding route to $SUBNET for $NODE on $NAME
>>> ip -6 route replace $SUBNET dev $INTERFACE
>>> Site 2:
>>> -----------------------
>>> tinc.conf:
>>> Name = rps
>>> AddressFamily = ipv6
>>> BindToAddress = 2001:1b40:5000:9::2
>>> ConnectTo = rsukmhb
>>> IffOneQueue = yes
>>> tinc-up:
>>> #!/bin/sh
>>> logger -t tinc Bringing up interface $INTERFACE
>>> ip -6 link set "$INTERFACE" up
>>> ip -6 link set "$INTERFACE" txqueuelen 10
>>> ip -6 addr add fdd1:c52a:3c24:3384::1/64 dev "$INTERFACE
>>> subnet-up:
>>> #!/bin/sh
>>> [ -z "$NAME" ] && exit 0
>>> [ "$NAME" = "$NODE" ] && exit 0
>>> logger -t tinc Adding route to $SUBNET for $NODE on $NAME
>>> ip -6 route replace $SUBNET dev $INTERFACE
>>> The VPN tun interfaces use private IPv6 IP addresses in the
>>> fdd1:c52a:3c24:3384::/64 range.
>>> I am then using the host entries at each site to advertise an IPv6
>>> /64 subnet used internally (although still publically routable 
>>> address
>>> subnet) so that it is routed over the VPN tunnel to the other side.
>>> This is working pretty well and I am getting around 80MBits/sec 
>>> throughput.
>>> However we have an cron process that runs every 1 minute and makes
>>> several HTTP requests over the VPN every 10s.
>>> About 10-12 times a day we are getting these errors after the
>>> specified 5 second connect timeout set in the app.
>>> Request failed: connect() timed out!
>>> If we disable the VPN and just route the requests over the internet
>>> (as I said they are publically routable addresses) then we do not 
>>> see
>>> these errors, suggesting this is not an application problem.
>>> We are also running Cacti and Nagios over the VPN for monitoring the
>>> remote site.
>>> The traffic level is low, averaging about 20 kbps, but quiet bursty,
>>> as every few minutes nagios/cacti runs, and the rest of the time the
>>> tunnel is quiet except for this cron app that makes a very small 
>>> HTTP
>>> request every 10s.
>>> Do you know what I could be looking at to fix this?
>>> I have found these posts that suggest a similar connect() timeout 
>>> issue:
>>> Page 12 of this doc:
>>> http://tinc-vpn.org/presentations/fosdem-2011/ec2_vpn_fosdem2011.pdf
>>> http://thr3ads.net/tinc-devel/2010/10/1964008-Tweaks-for-high-bandwidth-tinc
>>> I have tried disabled replay protection, setting IffOneQueue,
>>> lowering and increasing the txqueuelen, setting priority of the tinc
>>> process.
>>> None of these settings have improved things though.
>>> Any thoughts would be much appreciated.
>>> Thanks
>>> Tom