Strange IPv6 reachability problem

Jeroen Massar jeroen at
Mon Jun 20 01:22:17 CEST 2011

On 2011-06-20 01:06 , Seth Mattinen wrote:
> On 6/19/2011 3:38 PM, Jeroen Massar wrote:
>> On 2011-06-20 00:19 , Seth Mattinen wrote:
>> [..]
>>> I *can not* reach it from a server at my parent's house:
>>> source: 2607:fe70:1002:0:202:b3ff:fe30:f633
>>> dest: 2001:500:61:28::70
>>> PING 2001:500:61:28::70(2001:500:61:28::70) 56 data bytes
>> I suggest you try this magical tool called 'traceroute' or if available
>> tracepath6 it will open your eyes.
> What did I do to warrant such a rude response from you?

If that is 'rude' then you need to adjust your sensitivity meter.

This list is called ipv6-ops, not 'ipv6-user-helpdesk' as such you
should be aware of the simple network debugging tools and have the
ability to provide the most minimal amount of information when debugging

> There are no issues with my netflow, and if it's not crossing my border
> in to me then obviously tcpdump on the interface is even less useful.

Not if your netflow meter is broken, which has been seen on various
boxes already, but alas you did not provide any information on what kind
of box it might be thus that might remain a mystery.

Also from the next mail we can deduce that there is some kind of
firewalling happening, what kind exactly is again unknown. But that
might be causing issues.

> Plus I can reach plenty of other IPv6 addresses from this box, like
> Here's 2001:4860:4001:803::1012:

That is really great, but that just means that for that address you have
a working route, the internet is a big place though.


More information about the ipv6-ops mailing list