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Re: [K12OSN] ldap problems...HELP!!!



On Wed, 2003-07-30 at 17:00, Barry Smoke wrote:

> 2) since starting over from scratch on the server, re-loading redhat 
> 9...our putty terminals
> will drop our shell connections several times during the day....it is 
> very frustrating, and we have no idea what is causing it.
> when it happens, sometimes we can't log right back in, nad have to wait 
> a sec...the strange thing is that this server is the only one doing it...
> all 6 other linux servers have no problems..
> thinking it may be hardware related, we have tried disabling the onboard 
> gigabit nics in our server, and installing 2 new
> gigabit nic's, and we are still seeing the same thing...I have also 
> wondered if it was ldap related, and that ldap was runnign too slow to 
> keep up
> and everynow and then , connections would terminate

This sounds more like a network problem than software. Try ftp'ing
a large file between machines to see if you get decent throughput.
One thing that can easily cause these symptoms is a half/full duplex
mismatch between any two components in the path.  If there is only one
switch and the clients and servers both connect directly to it then
it has to be the server <-> switch connection.  'dmesg' on the server
should tell you the speed/duplex it chose during bootup.
/sbin/mii-tool will let you view the current setting or force a
change. If the switch is managed, it should have a console/telnet/web
interface to see and change settings.  If it isn't managed you may at
least have some lights to view the settings.If you have a mismatch, you
will drop packets that have to be corrected by high-level TCP timeouts
and retries which will completely destroy your throughput and cause lost
connections.  If there are other switches or routers involved, the same
thing applies to the interconnects.

Note that if you have hard-set full duplex on any managed component
instead of leaving it on auto, you must also hard-set the other end
of this connection to match.  Forcing a setting also turns off
negotiation, and the other end will have to assume half-duplex.

Since you mention using gigabit, you could also have trouble if
data coming from a gig switch has to traverse an overloaded 100
or 10M link.

---
  Les Mikesell
    les futuresource com





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