How to get the statistics info for one interface through linux command? - linux

Question

we know that some linux command can get tcp statistics info ,such as "netstat -s --tcp" ,"ss -s -t" , but how to get statistics for one specific interface ?

Answer 1

You can use tcpstat :
tcpstat - report network interface statistics
tcpstat -i <interface>
If you want to launch it when interface is up, you can use post-up in /etc/network/interfaces :
auto enp4s0f1
iface enp4s0f1 inet dhcp
post-up /etc/init.d/tcpstat start enp4s0f1
/etc/init.d/tcpstat is an init.d script, I have created containing :
#!/bin/bash
#title :tcpstat
#description :start/stop/restart tcpstat
#########################################
### install : cp tcpstat /etc/init.d/
# update-rc.d tcpstat defaults
### uninstall : update-rc.d -f tcpstat remove
usage(){
echo "Usage: service tcpstat {start|stop|restart} <interface>"
}
DEFAULT_LOCATION="/tmp/dump"
EXEC="/bin/tcpstat_run"
if [ ! -z "$2" ]; then
if [ ! -z "$3" ]; then
STORAGE_FILE="$3"
else
STORAGE_FILE="${DEFAULT_LOCATION}_$2"
fi
if [ -f $PID_FILE ]; then
echo "file exist"
fi
case "$1" in
start)
echo "Starting tcpstat service on inteface $2..."
daemonize -E INTERFACE=$2 -E DUMP_FILE=$STORAGE_FILE $EXEC
echo -e "\E[31;33m[ OK ]\E[0m"
;;
stop)
echo "Stopping tcpstat service..."
pkill -f "tcpstat -i $2"
echo -e "\E[31;33m[ OK ]\E[0m"
;;
restart|reload)
"$0" stop "$2"
"$0" start "$2"
;;
*)
usage
exit 1
esac
else
usage
fi
exit $?
Note that I have used daemonize instead of start-stop-dameon for RHEL compatibility.
daemonize launch the following exec located in /bin/tcpstat_run :
#!/bin/bash
tcpstat -i "$INTERFACE" > "$DUMP_FILE"&
You can modify these script to your liking especially if you want to save dump at a specific location & invoke special treatment in post-down.
For instance, if you try this as is, you will get following output :
user#user:~$ tail -f /tmp/dump_enp4s0f1
Time:1468847225 n=9 avg=66.56 stddev=35.76 bps=958.40
Time:1468847230 n=9 avg=87.33 stddev=40.17 bps=1257.60
Time:1468847235 n=14 avg=130.50 stddev=66.08 bps=2923.20
Time:1468847240 n=3 avg=46.00 stddev=0.00 bps=220.80
Time:1468847245 n=12 avg=58.50 stddev=11.26 bps=1123.20
Time:1468847250 n=9 avg=115.78 stddev=78.32 bps=1667.20
Time:1468847255 n=169 avg=135.22 stddev=188.26 bps=36564.80