System dropping interface conections

[Robert Holliday_1]

I have a K570 server runing 11.00. My users are complaining that they are loosing connections to the server. I checked the interface card using stm and nettlfmt and all seem well. I ran glance and saw packet data drops occur every 15-20 mins. During exceed x-session my connection was lost also. What can I do to find the route cause of this problem?

[Steven E. Protter · Accepted solution]

Couple of things:

run glance and watch the network display.

Install this product and run it in X
http://hpux.connect.org.uk/hppd/hpux/Gtk/Applications/ethereal-0.9.15/

Its a packet sniffer. If the problem is on the K box, or even it its not, you'll get good data on the issue.

You may want to do a few other things.

lanadmin -x 0

replace zero with the lan number from a lanscan display for the interface in question.

Make sure its running 100 BaseT full duplex, manual.

to make it manual, see my attached /etc/rc.config.d/hpbtlanconf file

Make sure the switch settings are consistent with my last two paragraphs.

See if the switch is workinig right or bottlenecking.

Check the organizations DNS structure and make sure authentication is happening to logical, nearby DNS servers. You may see authentication problems when you run the packet sniffer and this will help track and avoid these issues.

What kind of disk storage are you using?

SEP

[Uday_S_Ankolekar]

Do you have tmout activated anywhere?( like users profile or crontab etc)
export TMOUT=0 and see it makes any difference..

Also look at some of ndd parameters.

-USA..

[Bharat Katkar]

Also i would like to add something.

1.Check whether your NIC and switch port are in autonegotiate mode and similar Duplex settings.
2.Accordingly also check for the Client Systems in the network.
3.Check for any faulty NIC in the network producing heavy broadcasts.

Hope that helps.

Regards,

[Sanjay_6]

Hi,

Check and see if the switch port on which the system is connected is set to autoswitch. Also on the system what are the paramters for tha lan port. It should be set to 100, Full Duplex, Fixed and the same setting should be there on the switch.

A good guess about the problem you are facing is that the lan port or the switch is set to Auto-sense. Change it to Fixed (No Auto-Sense).

Hope this helps.

Regds

[Mel Burslan]

if you have an old windows pc that you can snatch for a few days, download this :

http://sourceforge.net/projects/packetyzer/

(based on ethereal but runs on windows)

or if you have a Linux running something

http://sourceforge.net/projects/etheral

(runs on *nix incl. and especially Linux)

and watch the traffic on the network segment where this is happening.

Sounds like your network is getting slammed every 15-20 minutes and starting to drop packets. With the sniffer, you can determine what exactly is happening when these drops occur.

My new motto:
Every journey into the unknown realm of IT starts with download of open source software.