l i n u x - u s e r s - g r o u p - o f - d a v i s
Next Meeting:
July 7: Social gathering
Next Installfest:
Latest News:
Jun. 14: June LUGOD meeting cancelled
Page last updated:
2011 Jan 08 23:04

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] Search Warrant Question re: IP Address Leases
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] Search Warrant Question re: IP Address Leases

   Dear Bob,

   I've set up Linksys routers for both my father and father-in-law which 
run OpenWRT. On the routers I run a cron job to periodically download a 
tiny file from my web site so I can see if the routers (and service) are 
up. Both connections are to Yahoo DSL, but I noticed that my father's 
connection keeps its IP address for weeks or months before changing, while 
my father-in-law's IP address changes about every day, randomly. I think 
the difference is in the reliability of the DSL modem or the amount of 
phone line noise - that the IP address would stay the same for a long 
time, unless the connection is interrupted, causing a new one to be 



On Fri, 7 Jan 2011, Bob Scofield wrote:

> I am in the process of analyzing a search warrant in a child porn case.
> Basically what happens is that the police search the web for child porn being
> downloaded by peer to peer programs.  They check the SHA 1 hashes against a
> database of known child pornography videos.  If the police see that child
> porn has been downloaded at an IP address they issue two search warrants.
> The first search warrant is directed at the ISP to see whom the subsciber was
> who had the IP address when the porn was downloaded.  After they get that
> information they then get a second search warrant to search all computers at
> the subscriber's address.
> This search warrant has challenged my understanding of dynamic IP addresses.
> I thought that a person was given an IP address each time he used the
> Internet.  I thought that after I left an Internet session my IP address was
> then made available to another customer of my ISP.  But in this case Comcast
> responded to the first search warrant with information about IP address
> leases.
> When I Google about IP address leases I'm reading about five and eight day
> leases.  But here is the information supplied by Comcast (IP address redacted
> by me):
> IP_Address	  Lease_Grant (UTC)	               Lease_Expire (UTC)
> xx.xxx.x.xxx     2010-08-23 02:56:44.0          2010-09-28 22:04:00.0
> xx.xxx.x.xxx     2010-04-08 06:28:58.0          2010-08-23 02:52:53.0
> I read this as saying that the defendant had the same IP address for about six
> months.  In fact the defendant may have had the same IP address for even
> longer as Comcast did not retain any records before April 8, 2010.
> So it seems to me that this dynamic IP address is like a static address.  Is
> this unusual?  Is the information provided by Comcast plausible?  Why would a
> lease be given for such a long period of time?  To track down people
> violating the law?
> Thank you.
> Bob
> _______________________________________________
> vox-tech mailing list
> vox-tech@lists.lugod.org
> http://lists.lugod.org/mailman/listinfo/vox-tech
vox-tech mailing list

LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
O'Reilly and Associates
For numerous book donations.