Connectivity issues and packet inspection

[Erik Kline]

2008/6/18 Steve Bertrand <steve at ibctech.ca>:
> Hi everyone,
>
> I'm having an issue internally here that I can't quite wrap my head around.
> I'll use noc.sixxs.net as my example case.
>
> One of my core routers installs the route after being received via BGP, and
> can reach it:
>
> Sending 5, 100-byte ICMP Echos to 2001:838:1:1:210:DCFF:FE20:7C7C, timeout
> is 2 seconds:
> !!!!!
>
> A box, connected via a switch to one of the router ports can ping the
> router, but not sixxs. (The same happens for ipv6.google.com). It appears
> the packets are not making the return trip.
>
> However, the same box that can not ping sixxs/google, can ping freebsd.org,
> so I know that I haven't broken everything.
>
> I have noticed some serious oddities within my router, and a few of the BGP
> peerings the last few days, so I'm sure it may have something to do with
> that, but I can't pinpoint it.
>
> Could a few kind souls have a look as to what kind of path they see to
> 2607:f118::/32, especially those who can not ping 2607:f118::b6?
>
> Also, something else I don't quite grasp. I believe it has something to do
> with source addr selection, but I'm just off to further delve into this now.
>
> This is a ping from a box to another box ::5 -> ::b6, both within the same
> prefix /64 (however there is one switch hop to make). The link-local addr is
> the router on the same prefix. I don't understand why there is an ICMP
> redirect involved in this situation (ie, why is the router involved at all).
> Can someone advise what I am missing?
>
> 19:56:27.669731 IP6 fe80::20b:46ff:fe3e:f341 > 2607:f118::5: ICMP6,
> redirect, 2607:f118::b6 to 2607:f118::b6, length 160
>
> 19:56:27.706583 IP6 fe80::20b:46ff:fe3e:f341 > 2607:f118::5: ICMP6,
> redirect, 2607:f118::b6 to 2607:f118::b6, length 160
>
> 19:56:27.713575 IP6 fe80::20b:46ff:fe3e:f341 > 2607:f118::5: ICMP6,
> redirect, 2607:f118::b6 to 2607:f118::b6, length 208
>
> 19:56:27.716855 IP6 fe80::20b:46ff:fe3e:f341 > 2607:f118::5: ICMP6,
> redirect, 2607:f118::b6 to 2607:f118::b6, length 192
>
> 19:56:27.869865 IP6 fe80::20b:46ff:fe3e:f341 > 2607:f118::5: ICMP6,
> redirect, 2607:f118::b6 to 2607:f118::b6, length 160
>
> 19:56:28.018445 IP6 fe80::20b:46ff:fe3e:f341 > 2607:f118::5: ICMP6,
> redirect, 2607:f118::b6 to 2607:f118::b6, length 120
>
> Steve
>
>
>

Possibly a configuration issue on the client?  I should think that ::5
should have been able to tell that ::b6 was on-net and used regular ND
to find it, rather than sending the ping to the router.  Is there any
config data for the (non-router) box?