Hello,
safebrowsing-cache.google.com is checked from both Google Toolbar
included by default in Firefox 3 and on Google Chrome Navigator.
Google Toolbar is also available on IE, etc.
When the query reaches the DNS of the ISP it will reply with a DNS TCP reply
if minimal-responses is no (default on Bind9) or with a small UDP DSN reply
if minimal-responses is yes.
I recommend that all ISP use minimal-responses yes or equivalent on their
DNS server. This will save bandwidth and avoid DNS TCP …
[View More]reply to be blocked
in a Firewall in the path.
Best Regards,
Guy Baconniere
http://www.divideandconquer.se/2009/06/25/firefox-30-freezes-waiting-to-res…
Add “minimal-responses yes;” in your bind9 configuration or ask your ISP
to do so.
/etc/bind/named.conf.options
options {
// …
// only add records to the authority and additional data sections when
required
minimal-responses yes;
};
By doing this Google’s safebrowsing-cache.google.com
will fit in a standard UDP DNS packet otherwise with additional section
it will be TCP DNS packet.
check the result with or without minimal-responses of
dig safebrowsing-cache.google.com
With minimal-responses no (default on Bind9)
IP (tos 0×0, ttl 64, id 40627, offset 0, flags [none], proto UDP (17),
length 75) 127.0.0.1.49553 > 127.0.0.1.53: [bad udp cksum 6429!] 40815+
A? safebrowsing-cache.google.com. (47)
IP (tos 0×0, ttl 64, id 40628, offset 0, flags [none], proto UDP (17),
length 526) 127.0.0.1.53 > 127.0.0.1.49553: 40815| q: A?
safebrowsing-cache.google.com. 25/2/0
safebrowsing-cache.google.com.[|domain]
IP (tos 0×0, ttl 64, id 4337, offset 0, flags [DF], proto TCP (6),
length 60) 127.0.0.1.57552 > 127.0.0.1.53: S, cksum 0×30e4 (correct),
272739230:272739230(0) win 32792
IP (tos 0×0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length
60) 127.0.0.1.53 > 127.0.0.1.57552: S, cksum 0×6453 (correct),
281541131:281541131(0) ack 272739231 win 32768
IP (tos 0×0, ttl 64, id 4338, offset 0, flags [DF], proto TCP (6),
length 52) 127.0.0.1.57552 > 127.0.0.1.53: ., cksum 0×4b76 (correct),
1:1(0) ack 1 win 513
IP (tos 0×0, ttl 64, id 4339, offset 0, flags [DF], proto TCP (6),
length 101) 127.0.0.1.57552 > 127.0.0.1.53: P 1:50(49) ack 1 win 513
5198+[|domain]
IP (tos 0×0, ttl 64, id 16739, offset 0, flags [DF], proto TCP (6),
length 52) 127.0.0.1.53 > 127.0.0.1.57552: ., cksum 0×4b46 (correct),
1:1(0) ack 50 win 512
14:44:32.883449 IP (tos 0×0, ttl 64, id 16740, offset 0, flags [DF],
proto TCP (6), length 632) 127.0.0.1.53 > 127.0.0.1.57552: P 1:581(580)
ack 50 win 512 5198 q:[|domain]
IP (tos 0×0, ttl 64, id 4340, offset 0, flags [DF], proto TCP (6),
length 52) 127.0.0.1.57552 > 127.0.0.1.53: ., cksum 0×48ef (correct),
50:50(0) ack 581 win 531
IP (tos 0×0, ttl 64, id 4341, offset 0, flags [DF], proto TCP (6),
length 52) 127.0.0.1.57552 > 127.0.0.1.53: F, cksum 0×48ee (correct),
50:50(0) ack 581 win 531
IP (tos 0×0, ttl 64, id 16741, offset 0, flags [DF], proto TCP (6),
length 52) 127.0.0.1.53 > 127.0.0.1.57552: F, cksum 0×4900 (correct),
581:581(0) ack 51 win 512
IP (tos 0×0, ttl 64, id 4342, offset 0, flags [DF], proto TCP (6),
length 52) 127.0.0.1.57552 > 127.0.0.1.53: ., cksum 0×48ed (correct),
51:51(0) ack 582 win 531
With minimal-responses yes
IP (tos 0×0, ttl 64, id 40623, offset 0, flags [none], proto UDP (17),
length 75) 127.0.0.1.40215 > 127.0.0.1.53: [bad udp cksum 8a13!] 55747+
A? safebrowsing-cache.google.com. (47)
IP (tos 0×0, ttl 64, id 40624, offset 0, flags [none], proto UDP (17),
length 494) 127.0.0.1.53 > 127.0.0.1.40215: 55747 q: A?
safebrowsing-cache.google.com. 25/0/0
safebrowsing-cache.google.com.[|domain]
Best Regards,
Guy Baconniere
[View Less]
Dear networkers,
I have an off-topic network problem, but some ppl here might help me. I
need to build an IP network line from the middle of a construction site
to an internet connection place for a one-time event. The distance is
around 500 - 1000m. No line of sight and therefore directed WLAN will
not work without several relays.
At the moment I'm thinking of using a copper line and some old fashioned
1MBit lease line modems. Do you have other ideas of getting this to work
or may have …
[View More]any parts which you can lend?
The event will happen at the end of July on a single week day. Thank you
for your help.
Cheerz,
- Dan
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Hi,
my 13 year old son will be giving a talk tomorrow in school
about "the internet". He has decided to focus in the talk on
the technical side, like fundamental principles of how DNS
resolution works. He has asked me if I could help him find
some datacenter-type equipment that he can show off to the
other students in his class. For example some rackmount
device and a bit of optical fibre, if possible. There is no
need for the stuff to be in working order.
Since the talk is tomorrow, we'…
[View More]d need to pick the stuff up today
in the afternoon or evening; I'd be happy to do this anywhere
is the Zurich or Zurich highlands (Zürcher Oberland) area. We'll
bring it back tomorrow in the afternoon after the talk.
We'd be very grateful if someone would help us with this!
Greetings,
Norbert
[View Less]
hi everybody
as steven is on holiday i am taking over his job. please find below the
announcement for the next beer event:
the facts for the next event:
-----------------------------
Date: 6th of July 2009
Time: starting around 18.30 o'clock
Location: @ the "el Lokal" (Gessner-Allee 11) in ZH
(www.ellokal.ch)
Registration deadline: 06.07.2009 12:00:00
-------------
Please register here: http://swinog.mrmouse.ch/ since we have to make
…
[View More]reservations, i need to know who's coming and who not. If you cannot
attend and you're registered please inform me asap (+41 79 2244933).
greetings
-roman
[View Less]
Hello,
We have since begin of this mount a new IP Rage /24. Our Mailservers has the IP Adresses 91.209.98.30 - 91.209.98.40.
Some of the IP are now used other in Reserve.
I think the IP Range was before we received it blacklistet on different systems. We was happy when the ISP like bluewin.ch can withelist this range...
The old Range 195.141.232.70/24 we will give back to ripe.
Greetings
Xariffusion Informatik & Telecom
X. Aerni
Xariffusion Informatik & Telecom
Administration
Zü…
[View More]richstrasse 10a
8340 Hinwil
Tel. 043 / 843 7878
Fax 043/843 7870
[View Less]
For those of you running some anti-spam solution, watch out for SORBS
disappearing. Amongst other products, it's part of a default
SpamAssassin config.
-- Matthias
-------- Original-Nachricht --------
Betreff: Imminent closure of SORBS.
Datum: Mon, 22 Jun 2009 12:26:39 +1000
Von: Michelle Sullivan <michelle_s-news(a)sorbs.net>
Organisation: Spam and Open Relay Blocking System
Newsgruppen: news.admin.net-abuse.email
All,
Please feel free to forward this message to any other location/…
[View More]mailing list.
It comes with great sadness that I have to announce the imminent closure
of SORBS. The University of Queensland have decided not to honor their
agreement with myself and SORBS and terminate the hosting contract.
I have been involved with institutions such as Griffith University
trying to arrange alternative hosting for SORBS, but as of 12 noon, 22nd
June 2009 no hosting has been acquired and therefore I have been forced
in to this announcement. SORBS is officially "For Sale" should anyone
wish to purchase it as a going concern, but failing that and failing to
find alternative hosting for a 42RU rack in the Brisbane area of
Queensland Australia SORBS will be shutting down permanently in 28 days,
on 20th July 2009 at 12 noon.
This announcement will be replicated on the main SORBS website at the
earliest opportunity.
For information about the possible purchase of SORBS, the source code,
data, hosts etc, I maybe contacted at michelle(a)sorbs.net, telephone +61
414 861 744.
For any hosting suggestions/provision, please be aware that the 42RU
space is a requirement at the moment, and the service cannot be made
into a smaller rackspace without a lot of new hardware, virtual hosting
is just not possible. The SORBS service services over 30 billion DNS
queries per day, and has a number of database servers with fast disk to
cope with the requirements.
Thank you for all your support over the years,
Michelle Sullivan
(Previously known as Matthew Sullivan)
[View Less]