Custom query (1015 matches)

I had a problem communicating with datatracker.ietf.org. With the help 
of Bill Fenner and some debugging we figured out that this is due to 
IPv6 MTU problem on the second hop from the hotel. You can't ping6 
2001:770:8:45::1 with 1500 bytes, but you can with 1300. In practice 
this means that anyone using IPv6 will have serious problems. I tested 
to www.kame.net and MTU of 1432+40+8=1480 works, but nothing higher than 
that. So presumably we have a 20 byte IPv4 tunnel header somewhere. 
ICMPv6 packet too bigs or something should be generated, or the tunnel 
MTU changed. Fragments seem to have a problem too.

Here's what's happening:

root@dummy3:/tmp# traceroute6 datatracker.ietf.org
traceroute to datatracker.ietf.org (2001:1890:1112:1::21) from 
2001:df8:0:16:216:6fff:fe75:6607, 30 hops max, 16 byte packets
 1  rtrextb-wireless-open.meeting.ietf.org (2001:df8:0:16::3)  8.519 ms  
1.457 ms  1.504 ms
 2  2001:770:8:45::1 (2001:770:8:45::1)  3.219 ms  3.129 ms  8.079 ms
 3  gig0-12-0-2-cr2-cwt.hea.net (2001:770:400:37::1)  8.505 ms  3.86 ms  
6.389 ms
 4  xe-2-1-0.dub20.ip6.tiscali.net (2001:668:0:3::c000:71)  3.134 ms  
16.201 ms  3.308 ms
 5  so-2-1-0.nyc22.ip6.tiscali.net (2001:668:0:2::1:421)  82.814 ms  
94.329 ms  88.522 ms
 6  so-3-0-0.was11.ip6.tiscali.net (2001:668:0:2::1:261)  101.731 ms  
88.808 ms  89.34 ms
 7  so-7-0-0.was10.ip6.tiscali.net (2001:668:0:2::1:232)  89.285 ms  
89.508 ms  94.378 ms
 8  ibr01-ve96.asbn01.occaid.net (2001:504:0:2:0:3:71:1)  92.142 ms  
90.306 ms
root@dummy3:/tmp#

root@dummy3:/tmp# ping6 -s 1434 www.kame.net
PING www.kame.net(orange.kame.net) 1434 data bytes

--- www.kame.net ping statistics ---
11 packets transmitted, 0 received, 100% packet loss, time 10010ms

root@dummy3:/tmp# ping6 -s 1432 www.kame.net
PING www.kame.net(orange.kame.net) 1432 data bytes
1440 bytes from orange.kame.net: icmp_seq=1 ttl=47 time=317 ms
1440 bytes from orange.kame.net: icmp_seq=2 ttl=47 time=300 ms

--- www.kame.net ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 300.619/308.966/317.313/8.347 ms

root@dummy3:/tmp# ping6 -s 1500 rtrextb-wireless-open.meeting.ietf.org
PING 
rtrextb-wireless-open.meeting.ietf.org(rtrextb-wireless-open.meeting.ietf.org) 
1500 data bytes
1508 bytes from rtrextb-wireless-open.meeting.ietf.org: icmp_seq=1 
ttl=64 time=9.48 ms
1508 bytes from rtrextb-wireless-open.meeting.ietf.org: icmp_seq=2 
ttl=64 time=6.31 ms

--- rtrextb-wireless-open.meeting.ietf.org ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 6.310/7.895/9.481/1.587 ms
root@dummy3:/tmp#

root@dummy3:/tmp# ping6 -s 1500 2001:770:8:45::1
PING 2001:770:8:45::1(2001:770:8:45::1) 1500 data bytes

--- 2001:770:8:45::1 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3010ms

root@dummy3:/tmp# ping6 -s 1300 2001:770:8:45::1
PING 2001:770:8:45::1(2001:770:8:45::1) 1300 data bytes
1308 bytes from 2001:770:8:45::1: icmp_seq=1 ttl=63 time=9.46 ms

--- 2001:770:8:45::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 9.463/9.463/9.463/0.000 ms

Jari

Hi,

Do you take issues with the hotel network? I'm trying to use PPTP based VPN tools via the ADSL in my room and failing miserably. Could PPTP pass through be enabled?

Note that everything seems fine via IETF wireless, it's JUST the house network that has this issue.

Thanks, Tony

The date displayed near the comments on ​http://ietf72.alcatel-lucent.com/ is not Dublin time. It looks like California time.