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Sven Trenkel
Works at Google
Attended TU Clausthal
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Sven Trenkel

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General reminder: Today is the last day you can share this without being a hypocrite.
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chao liu's profile photo
 
i am a student and i have read your paper:A Benchmarking Suite for Static Collision Detection Algorithm.i have some problem how can i connect you? its important to me...please
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Sven Trenkel

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Dear lazyplus,
are there any nice tools for dealing with prefix delegation on Linux (Debian)? Getting a /56 prefix from my ISP is easy enough with "dhclient -P", but it seems the client is by design unable to do anything with it except call a script.
So I need some tool to
1. Assign one /64 subnet to my LAN and bind one address to the interface
2. Hand out addresses to clients with radvd and dhcpd
3. Send dynamic updates to my DNS server
Are there any tool to make this easier or do I have to write a Python script from scratch?
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Norman Rasmussen's profile photo
 
I tend to cobble this together with some shell scripts. For radvd.conf I have a template with $ADDR that I replace with sed. ddclient can do dynamic updates for DNS hosting providers, but I've never used a client that does DNS spec dynamic updates.
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Sven Trenkel

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While flying to Tel Aviv, the alps from above. Sure lots of snow there.
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Sven Trenkel

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Two weeks ago in California: Nice 21°C.
Today in Germany: Fresh snow.
+Jan Dittmer: Bad time for a visit.

Oh well, didn't get white Christmas but at least white Easter.
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Jan Dittmer's profile photo
 
I just need to bring my skis...  Though hills are difficult to find in northern Germany.
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Sven Trenkel

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The current state of my Internet connection. But at least the packet loss is gone. Yayifications!
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Sven Trenkel's profile photoJan Dittmer's profile photo
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I got 22/5 - 100/10 runs around $370/month...
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Sven Trenkel

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+Paweł Zuzelski
Seen in MUC Central Station.
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Paweł Zuzelski's profile photoTobias Diedrich's profile photo
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For your instant LEGO fix :)
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Sven Trenkel

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After 6 days of not daring to touch my router because of oncall I finally configured it now. Most surprising lessons:
1. Linux' accept_ra is a tristate: 0=off, 1=on iff forwarding is off, 2=really on
2. Debian's dhclient will remove all addresses from an interface it's about to do dhcp on. So if you try to get a prefix delegation it will in fact kill your Internet connection.
3. Debian's dhclient does not execute user scripts, it sources them. So if you use exec or exit you're not getting any addresses at all.
4. dhcpd can not assign static IPv6 addresses based on the MAC address of the client and can not push an IPv6 default gateway. I'm sure that looked like a good idea at the time.

+Norman Rasmussen 
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Sven Trenkel's profile photoTobias Diedrich's profile photoJan Dittmer's profile photoWes Brown's profile photo
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You have to love a Boolean variable with three states ;-)
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Sven Trenkel

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Views from buildings.
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Sven Trenkel

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I figured out what this spring needed: More snow!
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Tobias Diedrich's profile photo
 
Just what I thought when looking out of the window this morning.
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Sven Trenkel

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Daily dose of #toilethumor
Seen at an unspecified time and place.
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Sven Trenkel

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Welches ist der unwichtigste Flughafen Deutschlands? Mehdorn hats herausgefunden: Hamburg.
Nachdem er erfolgreich die Deutsche Bahn zugrundegerichtet hat, ist jetzt AirBerlin dran.
Auf zur Lufthansa.
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Jan Dittmer's profile photoSven Trenkel's profile photo
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Sie haben beschlossen die Anzahl ihrer Fluege drastisch zu reduzieren. Und sie haben beschlossen, dass Hamburg nicht wichtig genug ist weiter beachtet zu werden, also dort 2/3 ihrer Fluege gestrichen. Sie haben ausserdem beschlossen, den Hamburger Flughafen darueber nicht vorher zu informieren, so dass er sich nicht um Ersatzfluege anderer Gesellschaften bemuehen konnte, also gibts ab Winter Engpaesse/Preiserhoehungen bis die anderen Linie reagieren und die wegfalleneden Fluege ersetzen.

Zeit den Weihnachtsurlaub zu buchen, solange es noch was zu buchen gibt ...
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Sven Trenkel

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My first personal IPv6 day collateral damage:
YouTube has AAAA records now + my Sixxs tunnel endpoint is in Germany => Most of YouTube is not available any more.
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Pim van Pelt's profile photoTobias Diedrich's profile photoSven Trenkel's profile photo
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I always used my own DNS resolver, not whitelisted with Google DNS. So for me it was all IPv4 and therefore no problem.

As for IPv6 NAT:
Aperture Science
We do what we must
because we can.
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Work
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  • Google
    Search SRE, 2011 - present
  • noris network
    Sysadmin, 2007 - 2011
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Education
  • TU Clausthal
    Informatik, 2000 - 2006
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