nanog mailing list archives

RE: NAT64 and matching identities


From: "Tony Hain" <alh-ietf () tndh net>
Date: Sat, 23 Nov 2013 11:22:10 -0800

So it turns out that in many cases a missing www is causing the "no IPv4"
response, and someone from Alexa does need to explain what is going on. For
the entire top-1m.csv file, 35,554 entries returned "no IPv4". For each
entry in the csv file;
some return NXDOMAIN:
discart.ru  -->  NXDOMAIN
     www.discart.ru resolves, but Alexa file missing www.
     Alexa position:            4721,discart.ru

some return without any answer:
bp.blogspot.com  --> No Answer
     www.bp.blogspot.com resolves, but Alexa file missing www.
     Alexa position:            87,bp.blogspot.com

while others point to MX-only entries:
akamaihd.net  -->  MX-only
     www.akamaihd.net resolves, but Alexa file missing www.
     Alexa position:            74,akamaihd.net

The version of the code I have been using strips the www. and tries again,
but obviously it also needs to add the www. and retry. In any case, the
Alexa file points to names that do not serve web content, so the entire 'top
1M' list is suspect.

Tony


-----Original Message-----
From: Tony Hain [mailto:alh-ietf () tndh net]
Sent: Friday, November 22, 2013 3:50 PM
To: 'Owen DeLong'
Cc: Sherfesee () amazon com; 'NANOG List'
Subject: RE: NAT64 and matching identities

Someone from Alexa really needs to answer how that list is created because
their web site discussion is way too hand-wavy, but given that neither of
those appear to be currently valid names, and 1.1.1.1 is on the list at
all, there
must be some measure of cross link and redirection occurrences. For the
entire top-1m, I show today's file has 2815 as dotted-quad. In the top
50,000 there are 1790 with "no IPv4   no IPv6".  Clearly they don't bother
to prune the list for validity. ~4% of the next 25,000 names are dead
(50,000-
75,000), and one can only guess that as you get further down the list the
percentage of dead names will continue to go up. I have a full 1M run in
process, but would not count on it completing before Monday.

Just to add a level of 'extra effort' to the process, I increased the
number of
attempts to 10, and the time between attempts to 10 seconds. With that,
dead names in the top 1000:
akamaihd.net                    no IPv4   no IPv6
bp.blogspot.com                 no IPv4   no IPv6
delta-search.com                no IPv4   no IPv6
bannersdontwork.com             no IPv4   no IPv6
cloudfront.net                  no IPv4   no IPv6
doorblog.jp                     no IPv4   no IPv6
uimserv.net                     no IPv4   no IPv6
linksynergy.com                 no IPv4   no IPv6
lipixeltrack.com                no IPv4   no IPv6
australianbrewingcompany.com    no IPv4   no IPv6
searchfun.in                    no IPv4   no IPv6
greatappsdownload.com           no IPv4   no IPv6
klikbca.com                     no IPv4   no IPv6
jobfindgold.info                no IPv4   no IPv6
adnxs.com                       no IPv4   no IPv6
rakuten.ne.jp                   no IPv4   no IPv6
sweetpacks-search.com           no IPv4   no IPv6
yomiuri.co.jp                   no IPv4   no IPv6
incredibar-search.com           no IPv4   no IPv6
searchgol.com                   no IPv4   no IPv6
livedoor.biz                    no IPv4   no IPv6
workercn.cn                     no IPv4   no IPv6

FWIW: in the top 50,000, I show 1525 "has IPv4  has IPv6" &  0  "no IPv4
has
IPv6". In other words, there are more dead names than there are AAAA
records, and there are not any IPv6-only sites in that group.

Tony


-----Original Message-----
From: Owen DeLong [mailto:owen () delong com]
Sent: Friday, November 22, 2013 1:48 PM
To: Tony Hain
Cc: joel jaeggli; Valdis.Kletnieks () vt edu; NANOG List
Subject: Re: NAT64 and matching identities

So one has to wonder how those names made it into the top 100 list if
it's supposed to be a top 100 web sites, since they are obviously not
web
sites.
(at least in the case of the two in the top 100)

Owen

On Nov 22, 2013, at 1:28 PM, Tony Hain <alh-ietf () tndh net> wrote:

The only thing it explicitly strips out are dotted-quads, which
don't occur until # 4255. The code makes five passes at
getaddrinfo() for
IPv4 before giving up, and then it checks for a leading www and if
that exists it strips it off and does the 5 tries loop again, then
later the same process for IPv6. For the top 100 run:
akamaihd.net                    no IPv4   no IPv6
bp.blogspot.com                 no IPv4   no IPv6

FWIW :::
Dotted-quad's in the top 10,000
4255,92.242.195.24
4665,1.1.1.1
5079,92.242.195.231
6130,1.254.254.254
9518,208.98.30.70

whois 92.242.195.24
...
netname:        Respina
descr:          BroadBand IP Pool
country:        IR
...
route:          92.242.195.0/24

Respina BroadBand IP Pool in the top 100,000
4255,92.242.195.24
5079,92.242.195.231
10059,92.242.195.233
23912,92.242.195.30
31520,92.242.195.111
35867,92.242.195.235
95233,92.242.195.129


-----Original Message-----
From: Owen DeLong [mailto:owen () delong com]
Sent: Friday, November 22, 2013 12:16 PM
To: joel jaeggli
Cc: Valdis.Kletnieks () vt edu; Tony Hain; NANOG List
Subject: Re: NAT64 and matching identities

It would be way more than 2 if it were CNAME, methinks.

Owen

On Nov 22, 2013, at 12:12 PM, joel jaeggli <joelja () bogus com> wrote:

On 11/22/13, 12:01 PM, Valdis.Kletnieks () vt edu wrote:
On Fri, 22 Nov 2013 10:18:27 -0800, "Tony Hain" said:

The top 100 websites: AAAA records and IPv6 connectivity
         count with A:       98   ( 98.000%)
      count with AAAA:       30   ( 30.000%)
Of the 30 hosts with AAAA records, testing connectivity to TCP/80:
   count with IPv6 ok:       30   (100.000%)

Statistics whoopsie, or are there actually 2 sites in the top100
that are IPv6-only?

IN CNAME ? or is that being accounted for.








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