Thursday, November 21, 2013

Creating custom SSH welcome messages

Creating custom SSH welcome messages using motd (message of the day) to protect and secure SSH logins by displaying warming message to UN-authorized users or display welcome or informational messages to authorized users.

  • Login to your server as root via SSH. 
  • sudo vim /etc/motd 
  • Now type in the message you want everyone to see.
 ######### Welcome to the Vishal's server #########
 ###         This is the webServer                               ###
 ###########################################

Save and Quit,

Logout of SSH then log back in, you will receive your new greeting!
 
 
 
 
 
 
...EnJoY...
Vishal Vyas

Monday, November 11, 2013

Linux Network Bandwidth check Script.

The following are two such scripts by joe miller. The first script counts the number of packets per second, received (RX) or sent (TX) on an interface, while the latter scripts measures the network bandwidth of incoming (RX) and outgoing (TX) traffic on an interface. For these scripts to work, you do not need to install anything.

Measure Packets per Second on an Interface

1.netpps.sh
 
#!/bin/bash
INTERVAL="1"  # update interval in seconds
if [ -z "$1" ]; then
        echo
        echo usage: $0 [network-interface]
        echo
        echo e.g. $0 eth0
        echo
        echo shows packets-per-second
        exit
fi
IF=$1
while true
do
        R1=`cat /sys/class/net/$1/statistics/rx_packets`
        T1=`cat /sys/class/net/$1/statistics/tx_packets`
        sleep $INTERVAL
        R2=`cat /sys/class/net/$1/statistics/rx_packets`
        T2=`cat /sys/class/net/$1/statistics/tx_packets`
        TXPPS=`expr $T2 - $T1`
        RXPPS=`expr $R2 - $R1`
        echo "TX $1: $TXPPS pkts/s RX $1: $RXPPS pkts/s"
done

Measure Network Bandwidth on an Interface

2.netpps.sh
 
#!/bin/bash
INTERVAL="1"  # update interval in seconds
if [ -z "$1" ]; then
        echo
        echo usage: $0 [network-interface]
        echo
        echo e.g. $0 eth0
        echo
        exit
fi
IF=$1
while true
do
        R1=`cat /sys/class/net/$1/statistics/rx_bytes`
        T1=`cat /sys/class/net/$1/statistics/tx_bytes`
        sleep $INTERVAL
        R2=`cat /sys/class/net/$1/statistics/rx_bytes`
        T2=`cat /sys/class/net/$1/statistics/tx_bytes`
        TBPS=`expr $T2 - $T1`
        RBPS=`expr $R2 - $R1`
        TKBPS=`expr $TBPS / 1024`
        RKBPS=`expr $RBPS / 1024`
        echo "TX $1: $TKBPS kb/s RX $1: $RKBPS kb/s"
done
The following screenshot shows the above two scripts in action.

=================================================

Another Command to check network Status .

# /sbin/ip -s link 

How to Install docker-compose CentOS7

 Install Docker-compose on CentOs7 Linux. yum install -y epel-release yum install -y python-pip pip install --upgrade pip pip install ...