Why and How to check network traffic in Linux ?

  Why ?

To check the network traffic in your Linux server for certain cases , you may use tcpdump or Wireshark as a GUI of it, this will help you to monitor and filter the network traffic in the OS level .

How ?

Below are commands for port and all ports as a sample example  :

1- The traffic for all income for specific port:

tcpdump -ni <net_dev> -s0 -w /path/to/"$HOSTNAME"_"$(date +%d-%m-%y)".pcap host <ip_host>

 2- To check traffic for specific or all traffics port in specific network device:

tcpdump -ni <net_dev>  host <host_ip> -l > /path/to/"$HOSTNAME"_"$(date +%d-%m-%y)".pcap

3- To check traffic for specific network device and source/destination :

ifconfig -a

tcpdump -i <device name>

tcpdump -i <device name> dst <IP>

tcpdump -i <device name> src <IP>

Why and How to search all your code text in Oracle DB codes ?

Why ?

In Oracle to search in all codes source text (any code written like package body , function ..etc) if you need to search for certain word or any text matched it will difficult to open each one to see whether it contain this text or not , thus; you need to run the below query to reach this .

How ?

Below are commands in sql to reach this:

select *

from dba_source

where upper(text) like upper('%SOMETEXT%');