Need script help for monitoring duplex settings

Shell Programming and Scripting
1

So I have a server I am trying to set up a script to send a Wall message notifying of my eth0 nic being set to 100 half duplex instead of 100 full duplex.

I know I am trying to read from /etc/sysconfig/network/ifcfg-eth0 to pull the parameters

STARTMODE=onboot
BOOTPROTO=static
ETHTOOL_OPTIONS='speed=100
duplex=half
autoneg=off'
IPADDR=192.168.62.80
NETMASK=255.255.255.0

So when in the above condition, activate alarm message to console every 20 seconds. I am very new to shell scripting so any and all help is welcome.

2

Are you looking to trap for the speed and duplex only?
And, is 100 full the only valid data - anything else is a problem?

3

yes, speed and duplex only. Auto-negotiate on is also something I am looking for but at the very least, 100 full duplex.
The reason is I have a few servers that have mysteriously switched settings to 100 half. I don't care how they changed, I just need to know asap so as to correct the condition before network communications get too out of hand.

4

Seems the speed isn't changing in any case but only the duplex mode. Since you already have ethtool available, here's a start:

DUPLEX=$(ethtool eth0 | sed -n 's/Duplex:\(.*\)/\1/p')
if [ $DUPLEX = Full ]
then
   # Do something
elif [ $DUPLEX = Half ]
   # Do something else
fi
5

This is just the starting point I need. Thank you so much! I'll plug in the parameters I need and post the results!

---------- Post updated at 01:22 PM ---------- Previous update was at 11:30 AM ----------

Pardon my lack of knowledge here but I seem to be getting syntax errors with the "fi" at the end of the file? I tried running the dos2linux command to ensure there are no weird characters at the end of the file. Am I missing something within?

starbuck:/home/acc4000d # ./duplex72
./duplex72: line 8: syntax error near unexpected token `fi'
./duplex72: line 8: `fi'

#!/bin/sh
DUPLEX=$(ethtool eth0 | sed -n 's/Duplex:\(.*\)/\1/p')
if [ $DUPLEX = Full ]
then
   echo "All is good in the neighborhood"
elif [ $DUPLEX = Half ]
    echo "Check eth0 settings, I am at 100 half duplex. Do IT NOW!!!"
fi
6

Oops, I forgot the second "then". As in

if [...]
then
    [...]
elif [...]
then
   [...]
fi

EDIT: Also, I bet the second echo is gonna throw an error when trying to print the exclamation marks. Use single quotes instead.

7

That worked like a charm, thanks!!!