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ackistler

join:2007-01-11
Aurora, IL
reply to justbits

Re: AT&T IPv6 6to4 is broken

I've had a working 6to4 connection for years (4 or 5 or so), and I am also recently broken

This is very annoying, since the desired behavior is to use IPv6 first if a name resolves to both IPv6 and IPv4 addresses. As more sites add IPv6 addresses, the inability to use IPv6 means IPv6-savvy customers are losing connectivity to those sites.

When I set up 6to4 originally, Hurricane Electric was providing the closest anycast relay router. If AT&T ever took over with their own, I never noticed.

$ tracepath 192.99.88.1
1: localmachine (192.168.a.b) 0.167ms pmtu 1492
1: localrouter (192.168.a.c) 1.566ms
2: adsl-ww-xx-yy-zz.dsl.emhril.sbcglobal.net (ww.xx.yy.zz) 47.580ms
3: dist2-vlan50.emhril.ameritech.net (68.22.72.67) 46.402ms
4: dist1-g2-1.emhril.sbcglobal.net (151.164.43.88) asymm 3 45.594ms
5: no reply
etc.

$ ping 192.99.88.1
PING 192.99.88.1 (192.99.88.1) 56(84) bytes of data.

--- 192.99.88.1 ping statistics ---
7 packets transmitted, 0 received, 100% packet loss, time 6000ms


ackistler

join:2007-01-11
Aurora, IL

Oops... More accurate to use the right anycast address.

$ tracepath 192.88.99.1
1: localmachine (192.168.a.b) 0.214ms pmtu 1500
2: localrouter (192.168.a.c) asymm 1 2.200ms pmtu 1492
3: dist2-vlan50.emhril.ameritech.net (68.22.72.67) 45.900ms
4: dist1-g2-1.emhril.sbcglobal.net (151.164.43.88) asymm 3 46.022ms
5: no reply
etc.

$ ping 192.88.99.1
PING 192.88.99.1 (192.88.99.1) 56(84) bytes of data.

--- 192.88.99.1 ping statistics ---
108 packets transmitted, 0 received, 100% packet loss, time 107029ms


ackistler

join:2007-01-11
Aurora, IL

BTW I thought it would be worthwhile to add that, for me:

I had 6to4 connectivity on Wednesday, May 30.
I didn't have 6to4 connectivity on Saturday, June 2.

I can't be certain about Thursday or Friday.

HTH



justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
Reviews:
·Comcast Business..

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365 days
That matches my data. The 6to4 address (192.88.99.1) stopped responding to ping & traceroute on May 30th. IPv6 connectivity lost around the same timeframe.

There is no technical reason why they couldn't just enable a route for the closest BGP4 route. (he.net in Chicago!) I foresee this as a method of forcing IPv4 static IP customers to buy static IPv6 addresses (via 6rd) from AT&T.

[edit: corrected date]


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET

said by justbits:

There is no technical reason why they couldn't just enable a route for the closest BGP4 route. (he.net in Chicago!)

I'm not in the midwest, but at work I have two AT&T business Internet connections. The primary Internet connection (fiber optic) routes 6to4 over the AT&T backbone from San Francisco to Los Angeles to Dallas where it is handed over to Hurricane Electric and their Dallas 6to4 relay (seems like a long way given that there are local HE.net gateways in San Jose and Fremont).
Our backup Internet connection is DSL and it doesn't have a route to any 6to4 relay.

I do not know if 6to4 to an AT&T relay ever worked here. Whenever I speak to someone from AT&T (rarely) I always bring up the subject of IPv6 and the answer is always something evasive along the lines of "we working on it, we don't have any details to share at this point, we don't know when it will be available". If any of those AT&T technicians and account representatives had ever mentioned that AT&T was operating a 6to4 relay I would have certainly tried it out.
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