Joe's Random Ramblings

I am trying to set up IPv6 on my Linux box which is connected to an AT&T DSL line.
Since the DSL modem only supports IPv4, I have set up an IPv6-to-IPv4 tunnel.
According to the IPv6 specs, this tunnel sends the IPv6 packets to the special "anycast" IPv4-address 192.88.99.1.
Update: The script I used to set up the tunnel is from here:
http://www.altocumulus.org/IPv6/
And the IPv6 routing table:

$: route -A inet6
Kernel IPv6 routing table
Destination                   Next Hop       Flags Metric Ref    Use Iface
::1/128                       ::             U     0      135      1 lo      
::75.3.241.4/128              ::             U     0      0        1 lo      
::/96                         ::             U     256    1        0 tun6to4 
2002:4b03:f104::1/128         ::             U     0      0        1 lo      
2002::/16                     ::             U     256    0        0 tun6to4 
2000::/3                      ::192.88.99.1  UG    1      109      0 tun6to4 
fe80::200:5aff:fe71:6c07/128  ::             U     0      0        1 lo      
fe80::211:11ff:febe:743e/128  ::             U     0      0        1 lo      
fe80::/64                     ::             U     256    0        0 eth0    
fe80::/64                     ::             U     256    0        0 eth1    
fe80::/64                     ::             U     256    0        0 tun6to4 
ff00::/8                      ::             U     256    0        0 eth0    
ff00::/8                      ::             U     256    0        0 eth1    
ff00::/8                      ::             U     256    0        0 tun6to4 

I tried an nslookup to see if things work:

$: nslookup
> set querytype=ANY
> ipv6.l.google.com
Server: 192.168.0.1
Address: 192.168.0.1#53

Non-authoritative answer:
ipv6.l.google.com has AAAA address 2001:4860:b002::68

So far, so good.

I then tried to ping ipv6.l.google.com, and that fails:

$: ping6 ipv6.l.google.com
PING ipv6.l.google.com(2001:4860:b002::68) 56 data bytes
^C
--- ipv6.l.google.com ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 2999ms

Seems that AT&T somewhere does not route to 192.88.99.1 correctly.
A traceroute shows:

$: traceroute 192.88.99.1
traceroute to 192.88.99.1 (192.88.99.1), 30 hops max, 38 byte packets
1 192.168.0.1 (192.168.0.1) 0.389 ms 0.295 ms 0.286 ms
2 adsl-75-3-255-254.dsl.irvnca.sbcglobal.net (75.3.255.254) 9.080 ms 6.618 ms 5.788 ms
3 dist1-vlan60.irvnca.pbi.net (67.114.48.130) 6.760 ms 6.202 ms 6.407 ms
4 bb1-p2-1.ksc2mo.sbcglobal.net (151.164.42.7) 5.838 ms 6.740 ms 6.345 ms
5 ex1-p13-0.eqlaca.sbcglobal.net (151.164.188.138) 7.729 ms 7.855 ms 7.360 ms
6 asn6939-he.eqlaca.sbcglobal.net (151.164.251.86) 7.319 ms 15.424 ms 7.344 ms
7 10gigabitethernet1-3.core1.pao1.he.net (72.52.92.21) 17.020 ms 16.658 ms 16.775 ms
8 * * *
...

So it seems that AT&T is handing this off to he.net, and there it just hangs.
Pretty lame.
I had an online chat with AT&T tech support, and they weren't much help, either. The first thing they said, of course, was "we don't support Linux". When I pointed out that Windows Vista also has IPv6 built-in, and that my question was about IPv6, not Linux, the tech support guy was staying on, but still, couldn't get me any useful information.

Update: The problem turned out to be the DSL modem, which seems to filter the tunneled IPv6 packets.

As a long time Slackware user, the recent announcement of Slackware 12.1 was a very welcome event. So I went to the Torrent download page to get the Slackware 12.1 DVD.
However, upon launching ktorrent, the KDE torrent client, to start the torrent download, my DSL connection went haywire. I had to reset the DSL modem (a Siemens SpeedStream 4100) and also reset the network port.
After searching for clues on the Net, I found that disabling DHT and limiting the number of connections (to 20 connections per torrent) solved the problem.