Connection failing between 2 nodes with dropped packets error

Wed Nov 12 20:51:05 CET 2014

Hi,

I'm sometimes getting a failure of connecting 2 nodes when Tinc is started
and configured in a LAN. In the logs, there are some unexpected dropped
packets with very high or negative seq. I can reproduce this issue ~2% of
the time.

When this happens, the 2 nodes can no longer ping or ssh each other through
the tunnel interface but using eth0 works fine. The connection can recover
after at least 20 minutes in some instances but sometimes the connection is
still broken after an hour.

Here is the tinc log on node3 after I sent the USR1 and USR2 signals:

2014-11-12 18:55:27 tinc.ccvpn[1879]: tincd 1.0.24 (Jul 12 2014 17:00:19)
starting, debug level 0
2014-11-12 18:55:27 tinc.ccvpn[1879]: /dev/net/tun is a Linux tun/tap
device (tun mode)
2014-11-12 18:55:28 tinc.ccvpn[1879]: Ready
2014-11-12 18:55:34 tinc.ccvpn[1879]: Got HUP signal
2014-11-12 18:56:41 tinc.ccvpn[1879]: Packet from node5 (10.60.19.106 port
655) is 1898092539 seqs in the future, dropped (1)
2014-11-12 19:00:53 tinc.ccvpn[1879]: Packet from node5 (10.60.19.106 port
655) is -1038452044 seqs in the future, dropped (2)
2014-11-12 19:01:29 tinc.ccvpn[1879]: Packet from node5 (10.60.19.106 port
655) is -2035506251 seqs in the future, dropped (3)
2014-11-12 19:05:07 tinc.ccvpn[1879]: Packet from node5 (10.60.19.106 port
655) is 1665101896 seqs in the future, dropped (4)
2014-11-12 19:06:45 tinc.ccvpn[1879]: Connections:
2014-11-12 19:06:45 tinc.ccvpn[1879]:  node1 at 10.60.19.107 port 40215
options 8 socket 7 status 00c2 outbuf 525/0/0
2014-11-12 19:06:45 tinc.ccvpn[1879]:  node5 at 10.60.19.106 port 53329
options 8 socket 8 status 00c2 outbuf 770/0/0
2014-11-12 19:06:45 tinc.ccvpn[1879]:  node4 at 10.60.19.101 port 57404
options 8 socket 16 status 00c2 outbuf 1049/0/0
2014-11-12 19:06:45 tinc.ccvpn[1879]:  node2 at 10.60.19.102 port 655
options 8 socket 3 status 01c2 outbuf 1566/0/0
2014-11-12 19:06:45 tinc.ccvpn[1879]:  node6 at 10.60.19.111 port 655
options 8 socket 20 status 01c2 outbuf 1630/0/0
2014-11-12 19:06:45 tinc.ccvpn[1879]: End of connections.
2014-11-12 19:06:48 tinc.ccvpn[1879]: Statistics for Linux tun/tap device
(tun mode) /dev/net/tun:
2014-11-12 19:06:48 tinc.ccvpn[1879]:  total bytes in:    76020994
2014-11-12 19:06:48 tinc.ccvpn[1879]:  total bytes out:   75874909
2014-11-12 19:06:48 tinc.ccvpn[1879]: Nodes:
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node1 at 10.60.19.107 port 655
cipher 91 digest 0 maclength 4 compression 0 options 8 status 001a nexthop
node1 via node1 pmtu 1454 (min 0 max 1518)
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node2 at 10.60.19.102 port 655
cipher 91 digest 0 maclength 4 compression 0 options 8 status 001a nexthop
node2 via node2 pmtu 1454 (min 0 max 1518)
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node3 at MYSELF cipher 0 digest 0
maclength 0 compression 0 options 8 status 0018 nexthop node3 via node3
pmtu 1518 (min 0 max 1518)
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node4 at 10.60.19.101 port 655
cipher 91 digest 0 maclength 4 compression 0 options 8 status 001a nexthop
node4 via node4 pmtu 1454 (min 0 max 1518)
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node5 at 10.60.19.106 port 655
cipher 91 digest 0 maclength 4 compression 0 options 8 status 001a nexthop
node5 via node5 pmtu 1454 (min 0 max 1518)
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node6 at 10.60.19.111 port 655
cipher 91 digest 0 maclength 4 compression 0 options 8 status 001a nexthop
node6 via node6 pmtu 1454 (min 0 max 1518)
2014-11-12 19:06:48 tinc.ccvpn[1879]: End of nodes.
2014-11-12 19:06:48 tinc.ccvpn[1879]: Edges:
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node1 to node2 at 10.60.19.102 port
655 options 8 weight 307
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node1 to node3 at 10.60.19.108 port
655 options 8 weight 320
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node1 to node4 at 10.60.19.101 port
655 options 8 weight 276
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node1 to node5 at 10.60.19.106 port
655 options 8 weight 349
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node1 to node6 at 10.60.19.111 port
655 options 8 weight 314
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node2 to node1 at 10.60.19.107 port
655 options 8 weight 307
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node2 to node3 at 10.60.19.108 port
655 options 8 weight 157
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node2 to node4 at 10.60.19.101 port
655 options 8 weight 329
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node2 to node5 at 10.60.19.106 port
655 options 8 weight 335
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node2 to node6 at 10.60.19.111 port
655 options 8 weight 181
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node3 to node1 at 10.60.19.107 port
655 options 8 weight 320
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node3 to node2 at 10.60.19.102 port
655 options 8 weight 157
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node3 to node4 at 10.60.19.101 port
655 options 8 weight 384
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node3 to node5 at 10.60.19.106 port
655 options 8 weight 348
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node3 to node6 at 10.60.19.111 port
655 options 8 weight 160
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node4 to node1 at 10.60.19.107 port
655 options 8 weight 276
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node4 to node2 at 10.60.19.102 port
655 options 8 weight 329
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node4 to node3 at 10.60.19.108 port
655 options 8 weight 384
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node4 to node5 at 10.60.19.106 port
655 options 8 weight 354
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node4 to node6 at 10.60.19.111 port
655 options 8 weight 430
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node5 to node1 at 10.60.19.107 port
655 options 8 weight 349
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node5 to node2 at 10.60.19.102 port
655 options 8 weight 335
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node5 to node3 at 10.60.19.108 port
655 options 8 weight 348
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node5 to node4 at 10.60.19.101 port
655 options 8 weight 354
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node5 to node6 at 10.60.19.111 port
655 options 8 weight 353
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node6 to node1 at 10.60.19.107 port
655 options 8 weight 314
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node6 to node2 at 10.60.19.102 port
655 options 8 weight 181
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node6 to node3 at 10.60.19.108 port
655 options 8 weight 160
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node6 to node4 at 10.60.19.101 port
655 options 8 weight 430
2014-11-12 19:06:48 tinc.ccvpn[1879]:  node6 to node5 at 10.60.19.106 port
655 options 8 weight 353
2014-11-12 19:06:48 tinc.ccvpn[1879]: End of edges.
2014-11-12 19:06:48 tinc.ccvpn[1879]: Subnet list:
2014-11-12 19:06:48 tinc.ccvpn[1879]:  172.23.1.0/24#10 owner node1
2014-11-12 19:06:48 tinc.ccvpn[1879]:  172.23.2.0/24#10 owner node2
2014-11-12 19:06:48 tinc.ccvpn[1879]:  172.23.3.0/24#10 owner node3
2014-11-12 19:06:48 tinc.ccvpn[1879]:  172.23.4.0/24#10 owner node4
2014-11-12 19:06:48 tinc.ccvpn[1879]:  172.23.5.0/24#10 owner node5
2014-11-12 19:06:48 tinc.ccvpn[1879]:  172.23.6.0/24#10 owner node6
2014-11-12 19:06:48 tinc.ccvpn[1879]: End of subnet list.
2014-11-12 19:08:08 tinc.ccvpn[1879]: Lost 318378807 packets from node5
(10.60.19.106 port 655)
2014-11-12 19:08:41 tinc.ccvpn[1879]: Packet from node5 (10.60.19.106 port
655) is 824328842 seqs in the future, dropped (1)
2014-11-12 19:09:41 tinc.ccvpn[1879]: Packet from node5 (10.60.19.106 port
655) is -673463260 seqs in the future, dropped (2)

Thanks,
Alexandre Beaulieu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tinc-vpn.org/pipermail/tinc/attachments/20141112/809ae97c/attachment.html>