network_hardware_problems_sniffers

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Subject: Re: Network Exerciser?
From: Rob Tanner <rtanner@cheshire.onlinemac.com>
Date: Wed, 20 Sep 2000 09:49:16 -0700

 --On 09/20/00 11:11:09 AM -0400 "Barry L. Kline" 
<blkline@attglobal.net> wrote:

> Does anyone know of a Linux-based piece of software for testing a
> TCP/IP network?   I have a segment of my network that's in another
> building which is connected by glass.  Machines over there are getting
> exquisitely slow response times and my supposition is that TCP/IP
> retries are occuring due to some flakey equipment.  Ping works fine to
> anything over there, yet any transmissions of sizeable data take
> forever.  I have two transceivers and two hubs that could be the
> problem and I don't have spares (currently.)
>
> I have hardware-based testing equipment for testing 10-BaseT but
> nothing that will cross the different media types.
>
> If there is a piece of software that would load up a network and give
> me some idea of the current stats I could start isolating each piece,
> using my laptop and another computer.  A google search hasn't turned
> up anything yet I'm sure that one must exist already.



What you're describing would suggest a problem with late collisions 
which fits your supposition of flaky hardware since that's the 
exclusive cause of late collisons.  The typical term for packets where 
late collisons have occurred is, I think, stub packets or snub or 
something like that.  Basically, they are short packets.

Any good sniffer should be able to discover them and report them, and 
suggest you look at ethereal -- it may or may not.  The URL is: 
http://ethereal.zing.org.

If I understand your network scenario correctly, the two pieces of your 
network are connected by hubs, so any late collisions will be 
detectable anyplace on the network, including your desk, and you can 
run a sniffer right from there.  If you have bridging or switching (or 
a router) anywhere in between, than that splits the collision domains, 
and the only thing you'll notice from your desk is slowness.  One other 
thing, if you're using switches and presuming they're not $1.98 K-Mart 
specials, thety are probably collecting bunches of useful performance 
statistics, including counts of late collisions.  Reset the counters so 
you have base and then just watch them.

===

Subject: Re: Network Exerciser?
From: John Aldrich <john@chattanooga.net>
Date: Wed, 20 Sep 2000 13:43:49 -0400

On Wed, 20 Sep 2000, Barry L. Kline wrote:
> Does anyone know of a Linux-based piece of software for testing a
> TCP/IP network?   I have a segment of my network that's in another
> building which is connected by glass.  Machines over there are getting
> exquisitely slow response times and my supposition is that TCP/IP
> retries are occuring due to some flakey equipment.  Ping works fine to
> anything over there, yet any transmissions of sizeable data take
> forever.  I have two transceivers and two hubs that could be the
> problem and I don't have spares (currently.)   
> 
Try MTR -- Matt's TraceRoute. It's a combination ping and traceroute.
It should show where the slowdown is occurring.
	John

===

Subject: Re: Network Exerciser?
From: John Aldrich <john@chattanooga.net>
Date: Wed, 20 Sep 2000 13:44:41 -0400

BTW, for the current version of MTR go to:
http://www.bitwizard.nl/mtr/

===

Subject: Re: [RHL] Apache Settings [more]
From: Kirk <kirk@death.prince-of-darkness.cc>
Date: Wed, 20 Sep 2000 10:40:13 -0700

>At 12:21 PM 9/20/00 -0500, you wrote:
>Finally I'm being asked for a password, but I'm getting "Authorization
failed, retry?" errors.
>
>Any ideas why? I'm using htpasswd, read several examples and the man page,
it's so simple it's hard to mess up. Permissions and directives are as
follows:
>
>[root@csc003 RedHatUpdates]# ls -l /etc/httpd/conf/httpd.conf
>-rw-r--r--    1 root     root        34087 Sep 20 12:05
/etc/httpd/conf/httpd.conf
>
><VirtualHost *IP_addresss_here*>
>    ServerAdmin wilson@claborn.net
>    DocumentRoot /Webhomes/Vanguard_mailer
>    ErrorLog logs/VanguardMailer-error_log
>    CustomLog logs/VanguardMailer-access_log common
>        <Directory /Webhomes/Vanguard_mailer>
>                AllowOverride AuthConfig
>        </Directory>
></VirtualHost>
>
>[root@csc003 RedHatUpdates]# ls -l /Webhomes/Vanguard_mailer/.htaccess
>-rw-r--r--    1 admin    users         128 Sep 20 11:33
/Webhomes/Vanguard_mailer/.htaccess
>
>[root@csc003 RedHatUpdates]# cat /Webhomes/Vanguard_mailer/.htaccess
>AuthType Basic
>AuthName "By Invitation Only"
>AuthUserFile /work/htpasswd.vanguard
>AuthGroupFile /dev/null
>require user *username_here*
>
>
>[root@csc003 RedHatUpdates]# ls -l /work/htpasswd.vanguard 
>-rw-r--r--    1 admin    users          23 Sep 20 12:08
/work/htpasswd.vanguard
>
>(which contains the username and some encrypted version of the password)
>
>Do any of those look wrong? Why else would Authorization fail? (note: it's
not because I'm typing the wrong password ;-)


If I recall correctly the AuthUserFile line needs to point with the
absolute path to the htpasswd file ex:
/home/webuser/public_html/directory/.htpasswd

AuthUserFile /absolute/path/to/.htpasswd
AuthGroupFile /dev/null
AuthName "Registered Users Only"
AuthType Basic
<Limit GET>
require valid-user
</Limit>


===


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