On Wed, 28 May 2003 17:43:45 +0300 (EEST), Kostas Kalevras wrote:
> On Wed, 28 May 2003, Pieter Droogendijk wrote:
> 
> > Greetings,
> >
> > I'm facing an odd problem at the moment.
> >
> > The ISP i work for has it's own radius servers, however we don't own the CVX.
> > The company that owns the CVX decided that it would be a good idea to
> > automatically reject a dialup connection if the connection process (which, of
> > course, includes our radius servers) takes longer then 6 seconds. And this
> > poses a problem.
> >
> > The solution we came up with, in the first place, was to disable the password
> > authentication. The new systems (which use freeradius) however, should include
> > authentication as well. But since the overall timeout is only 6 seconds, and
> > the LDAP gets some extreme loads at certain times, we can't reach that.
> >
> > I just benchmarked the server with an ldap timeout of 2 seconds (all three
> > ldap timeouts that is), and 10% of 500.000 requests were rejected because of
> > the timeout, which is unacceptable.
> 
> I believe that the bottleneck is the authentication part. The BIND operation
> requires a new connection (with all the corresponding overhead) as well as
> processing in the ldap server side (do a crypt() on the supplied password). If
> you are also using TLS (you don't say anything about it) then things will start
> getting out of hand. There's nothing you can do to the ldap module to fix that
> (it's how the LDAP protocol works). The only thing you can do is:
> 
> * Put the radius server on the same machine as the ldap server and use ldapi
> (ldap over unix sockets) if that is supported.

I already thought of running a local ldap mirror on the radius machine, and I'll start 
benchmarking this friday or next monday. I'll most certainly follow all (or at least 
most) of your advice. thanks.

> * Use the PAP/CHAP module and the password extraction mechanism of the ldap
> module so that you don't need to run the ldap module in the authentication fase.
> I believe that as long as your ldap server caches are working fine the
> authorization part of rlm_ldap will work just fine without timeouts.
> 
> >
> > What I need is something in between the two solutions; REJECT if the
> > authorization takes longer then X seconds, ACCEPT if the password
> > authentication takes longer then Y seconds, or send an ACCEPT or REJECT
> > according to succesful authorization and authentication responses, where
> > X+Y<6.
> >
> > Is there any valid way, besides patching the ldap module to make the return
> > value at timeouts configurable, that would solve this problem? Maybe someone
> > has another solution?
> >
> > Thanks in advance,
> >
> > Pieter Droogendijk
> >
> > --
> > There is an old time toast which is golden for its beauty.
> > "When you ascend the hill of prosperity may you not meet a friend."
> >             -- Mark Twain
> >
> > -
> > List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
> >
> 
> --
> Kostas Kalevras               Network Operations Center
> [EMAIL PROTECTED]     National Technical University of Athens, Greece
> Work Phone:           +30 210 7721861
> 'Go back to the shadow'       Gandalf
> 
> - 
> List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
> 


-- 
You love peace.

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