I'm running a tunnel from my OpenWRT box (MTU 1280) to ams1 tunnelbroker endpoint, all worked well for quite some weeks. I'm experiencing some weird packet loss, for example to facebook. A quick trace and ping gives me back these results:
PS C:\Users\Joris> tracert facebook.com
Tracing route to facebook.com [2a03:2880:2130:cf05:face:b00c:0:1]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms 2001:470:1f15:af4::1
2 11 ms 10 ms 10 ms jorisclaassen-2.tunnel.tserv11.ams1.ipv6.he.net [2001:470:1f14:b07::1]
3 17 ms 8 ms 15 ms v213.core1.ams1.he.net [2001:470:0:7d::1]
4 16 ms 22 ms 24 ms 100ge9-1.core1.lon2.he.net [2001:470:0:2d0::1]
5 82 ms 81 ms 87 ms 100ge1-1.core1.nyc4.he.net [2001:470:0:2cf::2]
6 85 ms 92 ms 93 ms 100ge11-1.core1.ash1.he.net [2001:470:0:299::1]
7 90 ms 87 ms 86 ms facebook-as32934.10gigabitethernet6.switch3.ash1.he.net [2001:470:0:1bf::2]
8 116 ms 118 ms 116 ms be11.bb02.iad3.tfbnw.net [2620:0:1cff:dead:beef::e2]
9 100 ms 99 ms 99 ms ae13.bb04.frc3.tfbnw.net [2620:0:1cff:dead:beef::12a6]
10 121 ms 121 ms 119 ms ae63.dr02.frc3.tfbnw.net [2620:0:1cff:dead:beef::615]
11 122 ms 125 ms 121 ms po1021.csw12c.frc3.tfbnw.net [2620:0:1cff:dead:beef::25d]
12 * * * Request timed out.
13 101 ms 100 ms 98 ms edge-star6-shv-12-frc3.facebook.com [2a03:2880:2130:cf05:face:b00c:0:1]
Trace complete.
PS C:\Users\Joris> ping facebook.com -n 10
Pinging facebook.com [2a03:2880:2130:cf05:face:b00c:0:1] with 32 bytes of data:
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=100ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=101ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=99ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=101ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=98ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=100ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=101ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=98ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=99ms
Reply from 2a03:2880:2130:cf05:face:b00c:0:1: time=98ms
Ping statistics for 2a03:2880:2130:cf05:face:b00c:0:1:
Packets: Sent = 10, Received = 10, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 98ms, Maximum = 101ms, Average = 99ms
PS C:\Users\Joris> ping facebook.com -n 10 -l 1500
Pinging facebook.com [2a03:2880:2130:cf05:face:b00c:0:1] with 1500 bytes of data:
Request timed out.
Any ideas?
The second box was of course stupid. Facebook just blocks these bigger ping packets. Still - the time before a page (facebook, google, youtube) loads is so high (20+ seconds) that I've unchecked IPv6 on my Windows box ATM. http://ipv6-test.com/pingtest/ gives ~60-80% packet loss to all servers.
Once again, any ideas?
You're on a tunnel trying packets that size? You are on (at the most) a tunnel with MTU 1480, and if you connect to your ISP over PPPOE, your tunnel needs to be set to 1472. You should be getting Packet too big errors reported:
~$ ping6 2001:470:1f14:af4::2 -s 1500
PING 2001:470:1f14:af4::2(2001:470:1f14:af4::2) 1500 data bytes
From 2001:470:0:7d::2 icmp_seq=1 Packet too big: mtu=1480
1508 bytes from 2001:470:1f14:af4::2: icmp_seq=2 ttl=54 time=242 ms
1508 bytes from 2001:470:1f14:af4::2: icmp_seq=3 ttl=54 time=242 ms
1508 bytes from 2001:470:1f14:af4::2: icmp_seq=4 ttl=54 time=242 ms
^C
--- 2001:470:1f14:af4::2 ping statistics ---
4 packets transmitted, 3 received, +1 errors, 25% packet loss, time 3003ms
Some ICMPv6 types must not/should not be blocked.
https://www.ietf.org/rfc/rfc4890.txt
All ICMPv6 traffic to my host is allowed. I'm running a tunnel with MTU 1280, on a FTTH solution in the Netherlands.
I think this might be the same issue as https://forums.he.net/index.php?topic=3428.0
To illustrate the issue, see this image:
(http://i.imgur.com/ptd5pif.png)
Are you sure that the mtu is configured on both sodes, i.e. HE website and your client?
Double checked, changed MTU in OpenWRT from 1280 to 1480, reflecting the tunnelbroker.net side.
Then verified the MTU in my Windows box:
PS C:\Users\Joris> netsh interface ipv6 show subinterfaces
MTU MediaSenseState Bytes In Bytes Out Interface
------ --------------- --------- --------- -------------
4294967295 1 0 212840 Loopback Pseudo-Interface 1
1480 1 66965 122638 Ethernet
1500 1 0 160152 VMware Network Adapter VMnet1
1500 1 0 160064 VMware Network Adapter VMnet8
Afterwards trying to ping google as an example
PS C:\WINDOWS\system32> ping google.com
Pinging google.com [2a00:1450:4013:c00::8b] with 32 bytes of data:
Request timed out.
Reply from 2a00:1450:4013:c00::8b: time=11ms
Reply from 2a00:1450:4013:c00::8b: time=13ms
Reply from 2a00:1450:4013:c00::8b: time=13ms
Ping statistics for 2a00:1450:4013:c00::8b:
Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 13ms, Average = 12ms
The ipv6-test website still states ~80% packet loss on ipv6 only.
But you don't need to change the MTU of your ethernet connection to 1480, just on the tunnel only.
It is set on the tunnel as well, so there should not be any problem there, or am I mistaken?
Quote from: jorisclaassen on June 18, 2015, 03:11:22 AM
It is set on the tunnel as well, so there should not be any problem there, or am I mistaken?
The MTU of your own Ethernet connection should match with that of your router.
The MTU of the tunnel configuration of your router should match with the setting on tunnelbroker.net.
If it is still not working, try another device. If trying another device does not work as well, email ipv6@he.net.
After testing my laptop (running Fedora) had no issues, I resinstalled.
Wanted to reinstall that box for quite some time, and frankly - it worked.
Thanks for the assistance anyways!