Disconnecting from Network

[K. Sivadasan]

Hi,

I am new to hp unix. Having Hp 9000 running hp os 10.20. Sometimes it suddenly gets disconnected from network. What are the network services i have to look. How to check whether it is up. And also pls tell me how to start the network service.

Thanks

Regards
Siva

[Vincenzo Restuccia]

/sbin/init.d/net [stop|start]

[Berlene Herren]

I would turn on verbose logging with #inetd -l, and look at the /var/adm/syslog/syslog.log for any messages where perhaps inetd died. Also, format your nettl.LOG00 and check for duplicate addresses.

#netfmt -f /var/adm/nettl.LOG00 > /tmp/log.out
#more /tmp/log.out

If you see a message like "trying to be our address," look the hex address that is doing the trying. You can then find out the manufacturer of that card by checking at

http://www.cavebear.com/CaveBear/Ethernet/index.html

or

http://www.normos.org/en/lists/ieee/all-ethernet.html

When your connection is lost, look to see if inetd is still running (#ps -ef | grep inetd). If not try to start it with
#/sbin/init.d/inetd start.

Regards,
Berlene

[Tim D Fulford]

Yet another tool is netfmt
# netfmt -t 10 /var/adm/nettl.LOG00
the t flag here means last 10 messages.

If you use ifconfig on your lan interfaces it will show wether they are up etc. Do this from the terminal (then you do not use the network!)

eg
# lanscan
Hardware Station Crd Hdw Net-Interface NM MAC HP-DLPI DLPI
Path Address In# State NamePPA ID Type Support Mjr#
8/0/2/0 0x0060B0B3ADC2 0 UP lan0 snap0 1 ETHER Yes 119
8/0/20/0 0x0010830379EA 1 UP lan1 snap1 2 ETHER Yes 119

here I have two lan cards on lan0 & lan1 to see how, say, lan0 is configured use ifconfig

# ifconfig lan0
lan0: flags=843
inet 158.234.78.137 netmask fffffc00 broadcast 158.234.79.255

Look for the UP flag as well as the rest.

I'm assuming the problems are intermittent

If connectivity just goes away & may recover you may have another device "spoofing" your IP address. In this case netfmt will say something appropriate.

If you have intermittent hardware type of problems then ifconfig may NOT show the UP flag. In this case you will need to restart the network for that lan card. you can use the previously suggested command
# /sbin/init.d/net

OR
Take the interface down
# ifconfig lan0 down
(Re)configure the interface
# ifconfig lan0 168.234.78.137 [netmask 255.255.252.0] up
If you are using standard netmasks then you can ignore the netmask bit.

As every one else has suggested you need more information etc

good luck

Tim