Forum - Tunnel pings fail checksum :: SixXS - IPv6 Deployment & Tunnel Broker

Tunnel pings fail checksum

Shadow Hawkins on Saturday, 25 February 2012 17:31:50

Hi, Starting one or two weeks ago, I get these messages in my syslog a few times a day:

Feb 25 07:34:01 server kernel: [3419359.925939] ICMPv6 checksum failed [2001:1418:0100:0257:0000:0000:0000:0001 > 2001:1418:0100:0257:0000:0000:0000:0002]

Obviously, these are the IP addresses of the tunnel endpoint and the tunnel server, so I think these are the tunnel-alive pings from sixxs. What could be the problem here? Regards Niki

Tunnel pings fail checksum

Shadow Hawkins on Sunday, 26 February 2012 02:28:15

Do you get these messages while running a ping6 with a presentable amount of replies? Is the tunnel lossy in general?

Tunnel pings fail checksum

Jeroen Massar SixXS Staff

on Sunday, 26 February 2012 13:23:56

Starting one or two weeks ago, I get these messages in my syslog a few times a day:

The pings happen every minute, how often do you see this? If you get checksum failures then the packet is mangled when it arrives at your host. A full packet capture would be useful, though it will not tell where packets are mangled.

Tunnel pings fail checksum

Shadow Hawkins on Sunday, 04 March 2012 13:35:29

I noticed the same "problem" while doing a packet trace (I have a Wireshark trace file proving this observation). It was one out of 43 traced ICMPv6 echo request packets received from PoP decgn01 (my tunnel: T81482) with an ICMPv6 checksum error. So my tunnel endpoint didn't reply to that damaged echo request. My endpoint device is a TP-LINK TL-MR3020 v1.0 with an OpenWRT firmware (see http://wiki.openwrt.org/toh/tp-link/tl-mr3020) with AICCU version 2007.01.15-console-linux.

Tunnel pings fail checksum

Shadow Hawkins on Thursday, 15 March 2012 02:52:56

I have the same messages a few times a day in my syslog of my openwrt router: Mar 15 00:27:31 tplink user.debug kernel: ICMPv6 checksum failed [2001:4dd0:ff00:091e:0000:0000:0000:0001 > 2001:4dd0:ff00:091e:0000:0000:0000:0002] Mar 15 00:28:31 tplink user.debug kernel: ICMPv6 checksum failed [2001:4dd0:ff00:091e:0000:0000:0000:0001 > 2001:4dd0:ff00:091e:0000:0000:0000:0002]

Tunnel pings fail checksum

Shadow Hawkins on Thursday, 15 March 2012 08:42:54

I happened to see them too. And I do not recall seeing them before this month. They seem to be "just a few each day" ... Mar 14 20:53:04 opensuse kernel: [16261720.921365] ICMPv6 checksum failed [2001:1938:0081:0209:0000:0000:0000:0001 > 2001:1938:0081:0209:0000:0000:0000:0002] Mar 14 22:12:05 opensuse kernel: [16266461.206845] ICMPv6 checksum failed [2001:1938:0081:0209:0000:0000:0000:0001 > 2001:1938:0081:0209:0000:0000:0000:0002] Mar 14 23:44:05 opensuse kernel: [16271981.237655] ICMPv6 checksum failed [2001:1938:0081:0209:0000:0000:0000:0001 > 2001:1938:0081:0209:0000:0000:0000:0002] These are the tunnel endpoints. -- R; <><

Tunnel pings fail checksum

Shadow Hawkins on Saturday, 24 March 2012 09:36:59

I am seeing the same error a few times a day. It started about a month ago, along the SixXS version update. Openwrt router - up-to-date trunk build. (The reason that Openwrt gets mentioned in this thread is probably due to its good logging, and users actually monitoring the logs.)

Tunnel pings fail checksum

Shadow Hawkins on Thursday, 29 March 2012 07:59:38

The same here. A few times a day. No obvious pattern. Is somebody interested to have a packet dump ? W.

Tunnel pings fail checksum

Shadow Hawkins on Wednesday, 11 April 2012 02:10:26

If you've got a dump I'll happily take a look at it.

Tunnel pings fail checksum

Shadow Hawkins on Friday, 27 April 2012 16:57:21

I'm getting these too, constantly. It started some time during 2011. First I thought a linux patch was the culprit, but now I'm not so sure anymore. Apr 27 04:47:47 kernel: [29343807.906316] ICMPv6 checksum failed [2001:14b8:0100:026f:0000:0000:0000:0001 > 2001:14b8:0100:026f:0000:0000:0000:0002] Apr 27 04:59:48 kernel: [29344604.300567] ICMPv6 checksum failed [2001:14b8:0100:026f:0000:0000:0000:0001 > 2001:14b8:0100:026f:0000:0000:0000:0002] I'm running Debian Lenny 2.6.26-2-amd64.

Tunnel pings fail checksum

Shadow Hawkins on Tuesday, 19 June 2012 18:05:42

I'm getting these too, every day, from two to ten times every day, the last:

Jun 19 17:42:43 lowpower4 kernel: [1440433.072390] ICMPv6 checksum failed [2001:1418:0100:0233:0000:0000:0000:0001 > 2001:1418:0100:0233:0000:0000:0000:0002]

I'm running Linux 3.2.12-gentoo #2 SMP Wed May 30 07:42:23 CEST 2012 x86_64 Intel(R) Atom(TM) CPU D525 @ 1.80GHz GenuineIntel GNU/Linux, net-misc/aiccu-2007.01.15-r1

Tunnel pings fail checksum

Shadow Hawkins on Sunday, 10 February 2013 10:39:13

OK, old issue, but thought I would still mention that it is still happening. Feb 9 22:30:15 e350 kernel: [1223465.207931] ICMPv6 checksum failed [2001:0960:0002:02c3:0000:0000:0000:0001 > 2001:0960:0002:02c3:0000:0000:0000:0002] Feb 9 23:01:15 e350 kernel: [1225324.208575] ICMPv6 checksum failed [2001:0960:0002:02c3:0000:0000:0000:0001 > 2001:0960:0002:02c3:0000:0000:0000:0002] Feb 10 01:55:21 e350 kernel: [1235764.009781] ICMPv6 checksum failed [2001:16d8:ff00:0002:0000:0000:0000:0001 > 2001:16d8:ff00:0002:0000:0000:0000:0002] Feb 10 06:05:16 e350 kernel: [1250750.557979] ICMPv6 checksum failed [2001:0960:0002:02c3:0000:0000:0000:0001 > 2001:0960:0002:02c3:0000:0000:0000:0002] Feb 10 08:19:16 e350 kernel: [1258786.281095] ICMPv6 checksum failed [2001:0960:0002:02c3:0000:0000:0000:0001 > 2001:0960:0002:02c3:0000:0000:0000:0002] Feb 10 08:30:22 e350 kernel: [1259451.857271] ICMPv6 checksum failed [2001:16d8:ff00:0002:0000:0000:0000:0001 > 2001:16d8:ff00:0002:0000:0000:0000:0002] Feb 10 09:46:23 e350 kernel: [1264009.526502] ICMPv6 checksum failed [2001:16d8:ff00:0002:0000:0000:0000:0001 > 2001:16d8:ff00:0002:0000:0000:0000:0002] Feb 10 10:14:17 e350 kernel: [1265682.611437] ICMPv6 checksum failed [2001:0960:0002:02c3:0000:0000:0000:0001 > 2001:0960:0002:02c3:0000:0000:0000:0002] It doesn't seem to be a huge problem, but only seem to occur with the pings from the two pops... Is there a way to disable the message for polluting my logs? :)

Tunnel pings fail checksum

Jeroen Massar SixXS Staff

on Sunday, 10 February 2013 21:23:34

but only seem to occur with the pings from the two pops...

ICMPv6 is a lot more than just echo requests and replies.

Is there a way to disable the message for polluting my logs? :)

Looks like you have a Linux kernel, you can disable the log verbosity of the kernel.

Tunnel pings fail checksum

Shadow Hawkins on Monday, 18 February 2013 21:18:24

Similar messages here. I have the impression that after this tunnel fails to respond. an AICCU restart will fix the issue. System: Linux 2.6.39-gentoo-r3

Tunnel pings fail checksum

Jeroen Massar SixXS Staff

on Monday, 18 February 2013 21:22:59

Similar messages here. I have the impression that after this tunnel fails to respond.

What do you mean with "after this tunnel fails to respond"? Can you provide more details?

an AICCU restart will fix the issue.

As effectively nothing is changed (tunnel parameters remain the same) when one restarts AICCU, how exactly do you think this changes anything?

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