[WEB4LIB] Hosts file limiting email questions

[Dan Lester]

Friday, February 16, 2001, 8:12:33 AM, you wrote:

JS> I'm going to try to implement the hosts file solution to blocking webmail
JS> and chat on our public workstations.  I'm mostly working from Eric Schnell's
JS> web site:
JS> http://bones.med.ohio-state.edu/eric/email.html

As always, good things from Eric.

JS> I'm starting with the little hosts file he uses and modifying it.  I've also
JS> taken the blacklist that Dan Lester put up on the web and have sorted out
JS> all addresses containing the strings "mail" or "chat".  However, that leaves
JS> me with a very long list of sites.  Will it slow things down if the
JS> hosts.sam file is long?
JS> (Dan's list is at http://www.riverofdata.com/tools/blacklist.htm )

First, you might just want to use the whole list.  There aren't over 2
percent of the sites on the list that are other than chat or email,
and they're game sites, which you might want to block as well.  We
didn't block game sites at first, but after getting a couple of heavy
duty chess and checker players camping out on terminals, we went ahead
and blocked them too.  Also, most of the sites that don't have the
words 'chat' or 'mail' in them still have those functions, such as
www.barracudas.com  or  www.basketballcrazy.com

As you know, I do it with a proxy server, and the size makes no
difference that I can tell. The entire list is kept in memory, so the
length doesn't make much difference (at least in expanding from 300
items to about 3,000).  I'd assume (with all the attendant dangers)
that whether it was a problem in a hosts file would depend on the
speed and RAM of the workstation in question.  I don't think I'd want
to do it on some of our public workstations that are P200s with 32mb,
Win95, IE5.5.

JS> Second question, can it stop part of a site, like go.msn.com/mail/, but not
JS> go.msn.com  (Not a working example, but that's the idea).

With our proxy software, yes.  I would assume so with other techniques
as well.  You'll notice on our blacklist that we block mail.msn.com,
but not msn.com, as well as examples of the sort you give.  In some
cases we block an explicit login page so that we don't block other
content on the site.

As always, we appreciate updates, corrections, deletions from the
blacklist.

JS> I'm thinking of monitoring a workstation with WinGuardian to try to find
JS> other sites our students are using, but I have to take Deep Freeze off
JS> whichever station I do that with.

I just get reports from reference staff of the sort that "someone was
chatting on station W7 about 3pm today" and I check the proxy server
log.  Also, at times like now (late Friday afternoon when I'm not up
to doing much else), I'll search through the proxy logs for words like
"mail" and "chat" and find some new ones.  We have one young lady who
seems to have a mission in life of finding a new chat site every day
or so.  So I block them as she finds them.

JS> We've got lots of Japanese students who used to use Xoom, which seems to be
JS> Nbci.com now.  I can't figure out how to block that without blocking all of
JS> nbci.com?

A quick look suggests that  http://home.nbci.com/main/register/signin/
would do it.  Sometimes you have to try a couple of options to find
the various ways into the site, but the above looks like it would
block all signins, which might be just what you want.

JS> Does anyone else want to share their blocking lists?

If so, please send copies to me and I'll merge them into the one I
maintain above.

Happy Holiday weekend, at least to those in USA who get three days.

dan


-- 
Dan Lester, Data Wrangler  dan at RiverOfData.com
3577 East Pecan, Boise, Idaho  83716-7115 USA
www.riverofdata.com  www.postcard.org  www.gailndan.com