tcpdump-examples

Sort By memory Usage per-process in the interactive menu

• press Shift+f to enter the interactive menu
• press the up or down arrow until the %MEM choice is highlighted
• press s to select %MEM choice
• press enter to save your selection
• press q to exit the interactive menu

top sort by memory

tcpdump-examples

In networking, a port is a virtual place on a machine that is open to connections from other machines. Every networked computer has a standard number of ports, and each port is reserved for certain types of communication.

Think of ports for ships in a harbor: each shipping port is numbered, and different kinds of ships are supposed to go to specific shipping ports to unload cargo or passengers. Networking is the same way: certain types of communications are supposed to go to certain network ports. The difference is that the network ports are virtual; they are places for digital connections rather than physical connections.


## DNS Port
Most of the time, DNS happens over UDP port 53. It's lightweight and faster than TCP.  This is to reduce performance overhead on the DNS server due to the number of requests it is likely to receive. 

But DNS servers still need to be available on TCP. Zone transfers happen over TCP port 53.  This happens on the DNS server side which is not related to the end-user. 

tcpdump-examples

In networking, a port is a virtual place on a machine that is open to connections from other machines. Every networked computer has a standard number of ports, and each port is reserved for certain types of communication.

Think of ports for ships in a harbor: each shipping port is numbered, and different kinds of ships are supposed to go to specific shipping ports to unload cargo or passengers. Networking is the same way: certain types of communications are supposed to go to certain network ports. The difference is that the network ports are virtual; they are places for digital connections rather than physical connections.

DNS Port

Most of the time, DNS happens over UDP port 53. It's lightweight and faster than TCP. This is to reduce performance overhead on the DNS server due to the number of requests it is likely to receive.

But DNS servers still need to be available on TCP. Zone transfers happen over TCP port 53. This happens on the DNS server side which is not related to the end-user.

tcpdump-examples

CrazyGames is a free online games website with more than 10 million active users monthly. The company was founded in 2014 by Tomas and Raf Mertens and has grown to 9 people.

The platform features games ranging from 3D shooters to puzzle games. The most popular categories are driving games, clicker games, minecraft games, stickman games, and .io games.CrazyGames is a member of KBC Start-it.

CrazyGames - An Amazing Free Online Game Website

Technologies

tcpdump-examples

DNS is short for Domain Name System. It is simply a database that links meaningful names (known as hostnames), such as howtouselinux.com, to a specific IP address, such as 185.230.63.171.

Each device connected to the Internet has a unique IP address. With the system of DNS, we don't have to memorize IP addresses.

DNS records

All domains are required to have at least a few essential DNS records for a user to be able to access their website using a domain name. This is the key concept of DNS.

Here are 4 commonly used DNS records.

tcpdump-examples

find命令特点：文件查找，实时查找，速度略慢，精确匹配

使用格式：# find [options] [查找路径] [查找条件] [处理动作]

查找路径：默认为当前目录

查找条件：默认为查找指定路径下的所有文件

处理动作：默认为显示

tcpdump-examples

Python3 打开 https 链接,异常：“SSL: CERTIFICATE_VERIFY_FAILED” 一、问题 Python2.7.9 之后，当使用urllib.urlopen打开一个 https 链接时，会验证一次 SSL 证书。而当目标网站使用的是自签名的证书时就会抛出如下异常：

<urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)>

二、解决方案 1，方案一 使用ssl创建未经验证的上下文，在urlopen中传入上下文参数：

tcpdump-examples

Python 列表

序列是Python中最基本的数据结构。序列中的每个元素都分配一个数字 - 它的位置，或索引，第一个索引是0，第二个索引是1，依此类推。

Python有6个序列的内置类型，但最常见的是列表和元组。

序列都可以进行的操作包括索引，切片，加，乘，检查成员。

此外，Python已经内置确定序列的长度以及确定最大和最小的元素的方法。

tcpdump-examples

python append描述 append函数可以在列表的末尾添加新的对象。函数无返回值，但是会修改列表。

append语法

list.append(object) 名称 说明 备注 list 待添加元素的列表 object 将要给列表中添加的对象 不可省略的参数 3 examples to append list in python

tcpdump-examples

用途 find命令用于在指定目录下查找文件。

全称 无

参数

-name ：后跟需要匹配的文件名模式，需要使用引号引起来