Forum - Received packet didn't start with a 6, thus is not IPv6 :: SixXS

Received packet didn't start with a 6, thus is not IPv6

Carmen Sandiego on Friday, 21 March 2008 00:53:42

Hi, During the last two or three weeks I'm getting the following message in /var/log/messages and on the console every couple of minutes: Received packet didn't start with a 6, thus is not IPv6 All works fine. I can't remember having made a change to provoke this behaviour. I suspect it's due to some software change on the server, but I don't know which. Here is a fifteen minute excerpt from /var/log/messages: http://huis.heesakkers.info/~oliver/IPv6messages3 In that fifteen minute period tcpdump -nAs 2048 port 5072 recorded the following: http://huis.heesakkers.info/~oliver/IPv6dump3 When matching the two, this remains: http://huis.heesakkers.info/~oliver/IPv6matches3 I'm running FreeBSD 6.2-RELEASE-p11 and latest sixxs-aiccu from ports (recompiled recently as part of the troubleshooting) Tunnel: T11203 (ayiya on nlams05) Username: OHA1-SIXXS pf firewall in place, but disabling it did not affect the problem. ifconfig:

vr0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet6 fe80::250:8dff:fe51:5d19%vr0 prefixlen 64 scopeid 0x1 inet 192.168.1.1 netmask 0xffff0000 broadcast 192.168.255.255 inet6 2001:610:6ce:1::1 prefixlen 64 ether 00:50:8d:51:5d:19 media: Ethernet autoselect (100baseTX <full-duplex> ) status: active plip0: flags=108851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST,NEEDSGIANT> mtu 1500 lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 inet 127.0.0.1 netmask 0xff000000 pflog0: flags=141<UP,RUNNING,PROMISC> mtu 33208 pfsync0: flags=41<UP,RUNNING> mtu 2020 syncpeer: 224.0.0.240 maxupd: 128 tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 inet6 fe80::250:8dff:fe51:5d19%tun0 prefixlen 64 scopeid 0x6 inet6 fe80::410:600:3a1:2%tun0 prefixlen 64 scopeid 0x6 inet6 2001:610:600:3a1::2 --> 2001:610:600:3a1::1 prefixlen 128

netstat -rn:

Internet: Destination Gateway Flags Refs Use Netif Expire default 192.168.1.254 UGS 0 9427945 vr0 127.0.0.1 127.0.0.1 UH 0 8904 lo0 192.168.0/16 link#1 UC 0 0 vr0 192.168.1.1 00:50:8d:51:5d:19 UHLW 1 12 lo0 192.168.1.2 00:16:17:12:a8:44 UHLW 1 39359 vr0 612 192.168.1.68 00:18:de:54:44:b3 UHLW 1 46 vr0 876 192.168.1.71 00:40:8c:7a:f3:6c UHLW 1 29466 vr0 486 192.168.1.93 00:91:00:00:7c:2f UHLW 1 702954 vr0 727 192.168.1.254 00:14:7f:10:e0:22 UHLW 2 1423 vr0 1200 192.168.255.255 ff:ff:ff:ff:ff:ff UHLWb 1 2055 vr0 Internet6: Destination Gateway Flags Netif Expire ::/96 ::1 UGRS lo0 => default 2001:610:600:3a1::1 UGS tun0 ::1 ::1 UHL lo0 ::ffff:0.0.0.0/96 ::1 UGRS lo0 2001:610:600:3a1::1 link#6 UHL tun0 2001:610:600:3a1::2 link#6 UHL lo0 2001:610:6ce:1::/64 link#1 UC vr0 2001:610:6ce:1::1 00:50:8d:51:5d:19 UHL lo0 2001:610:6ce:1:216:17ff:fe12:a844 00:16:17:12:a8:44 UHLW vr0 fe80::/10 ::1 UGRS lo0 fe80::%vr0/64 link#1 UC vr0 fe80::216:17ff:fe12:a844%vr0 00:16:17:12:a8:44 UHLW vr0 fe80::250:8dff:fe51:5d19%vr0 00:50:8d:51:5d:19 UHL lo0 fe80::%lo0/64 fe80::1%lo0 U lo0 fe80::1%lo0 link#3 UHL lo0 fe80::%tun0/64 link#6 UC tun0 fe80::250:8dff:fe51:5d19%tun0 link#6 UHL lo0 fe80::410:600:3a1:2%tun0 link#6 UHL lo0 ff01:1::/32 link#1 UC vr0 ff01:3::/32 ::1 UC lo0 ff01:6::/32 link#6 UC tun0 ff02::/16 ::1 UGRS lo0 ff02::%vr0/32 link#1 UC vr0 ff02::%lo0/32 ::1 UC lo0 ff02::%tun0/32 link#6 UC tun0

So, is there something I can do to get rid of this message (other than redirecting the aiccu-output)? Many thanks in advance. Greets, Oliver Heesakkers

Received packet didn't start with a 6, thus is not IPv6

Carmen Sandiego on Saturday, 22 March 2008 23:58:54

Is nobody else seeing these messages? On further investigation I took a laptop and did a fresh install of FreeBSD 6.2 on it. Customized the kernel in a similar fashion as the server and tried aiccu on that. --> same message Then did a fresh install of FreeBSD 6.3: GENERIC kernel --> same message, custom kernel --> same message. Then did a fresh install of FreeBSD 7.0: GENERIC kernel --> same message. Tired of that game I tried changing my tunnel-type, but it seems my speedtouch 716 can't work protocol 41 reliably, I was never able to ping my PoP IPv6 Endpoint, no traffic ever came back, if it even reached the PoP.

{Administrator}[nat]=>mapadd intf = Internet [type] = NAT [outside_addr] = 86.80.52.251 [inside_addr] = 192.168.1.1 [access_list] = [foreign_addr] = 192.87.102.107 [protocol] = 41 [outside_port] = [inside_port] = :nat mapadd intf=Internet type=nat outside_addr=86.80.52.251 inside_addr=192.168.1.1 foreign_addr=192.87.102.107 protocol=6to4

So I'm back with ayiya and the "packet didn't start with a 6"-messages keep on coming. Next step is probably dragging the laptop to a friends house, to see if it's the internet connection.

Received packet didn't start with a 6, thus is not IPv6

Shadow Hawkins on Tuesday, 01 April 2008 21:24:09

Well, if it's the internet connection, it must be my connections as well. Both at home with a fresh FreeBSD 7.0-RELEASE install over Orange ADSL and at work on a FreeBSD 6.2-STABLE machine connected via Signet I get the same messages. Even worse: with both installs my connection stops working after a few megabytes of traffic. [edwinm@joshua ~]$ ping6 www.sixxs.net PING6(56=40+8+8 bytes) 2001:610:600:47d::2 --> 2001:838:1:1:210:dcff:fe20:7c7c ping6: sendmsg: No buffer space available ping6: wrote noc.sixxs.net 16 chars, ret=-1 ping6: sendmsg: No buffer space available ping6: wrote noc.sixxs.net 16 chars, ret=-1 Mind you: this connection works after a fresh start of sixxs-aiccu, but stops working when a few MB's of data have been transferred. The 7.0 machine has no firewall enabled.

Received packet didn't start with a 6, thus is not IPv6

Shadow Hawkins on Thursday, 01 May 2008 21:35:13

I'm having the same problems here. I changed nothing, a few months ago these messages started appearing in the syslog: May 1 21:31:39 server aiccu: [AYIYA-tun->tundev] [192.87.102.107]:5072 : Received packet didn't start with a 6, thus is not IPv6 They appear about every two minutes. Any ideas?

Received packet didn't start with a 6, thus is not IPv6

Shadow Hawkins on Thursday, 01 May 2008 22:20:06

It's clearly a problem with the Ayiya hearbeat protocol. The message is generated by the heartbeat receiver. Apparently there is a mismatch of what is sent and expected. You can read this in file common/ayiya.c. Report it to SixXS.

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