Network

# --- MY Global IP
host myip.opendns.com resolver1.opendns.com
# --- or
dig +short myip.opendns.com @resolver1.opendns.com
# --- or
dig TXT +short o-o.myaddr.l.google.com @ns1.google.com
# --- or
dig +short txt ch whoami.cloudflare @1.0.0.1
# --- MY IPv6 address
dig -6 TXT +short o-o.myaddr.l.google.com @ns1.google.com

# Ethernet контроллеры
lspci | grep Ethernet
# сетевые интерфейсы, IP-адреса и многое другое
ifconfig
# быстрый просмотр всех доступных интерфейсов
ip a
# более подробная информация об интерфейсах
sudo lshw -class network

# --- nc
# проверка открытия порта 22
nc -zvw3 gitlab.misuz.ru 22
# nc: connect to gitlab.misuz.ru port 22 (tcp) failed: Connection refused
nc -zvw3 gitlab.misuz.ru 2281
# Connection to gitlab.misuz.ru 2281 port [tcp/*] succeeded!

# --- nmap
nmap gitlab.misuz.ru -p 443
# Starting Nmap 7.70 ( https://nmap.org ) at 2019-07-27 08:04 MSK
# Nmap scan report for gitlab.misuz.ru (94.233.205.208)
# Host is up (0.0041s latency).

# PORT    STATE  SERVICE
# 443/tcp closed https

# Nmap done: 1 IP address (1 host up) scanned in 13.04 seconds
# описание STATE см. по ссылке https://nmap.org/man/ru/man-port-scanning-basics.html

netstat -ant
Активные соединения с интернетом (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State      
tcp        0      0 127.0.1.1:53            0.0.0.0:*               LISTEN     
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN
sudo netstat -tapen
Активные соединения с интернетом (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State       User       Inode       PID/Program name
tcp        0      0 127.0.1.1:53            0.0.0.0:*               LISTEN      0          20930       1513/dnsmasq    
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      121        19019       1492/postgres

#
# Basic Auth
#
curl --user name:password http://www.example.com
curl --proxy-user proxyuser:proxypassword curl.haxx.se

# GET request с user-agent и follow-redirect
curl -A "Mozilla/5" -L https://s3.docshell.ru

#
# Post Request
#
curl --user user:secret \
    -H "Content-type: application/json" \
    -X POST \
    -d '{"company": {"name": "xxx", "number": "00000", "country": "Russian Federation", "url": "http://yandex.ru"}}' \
    http://localhost:3000/companies

#
# Pretty Output
#
curl -H "Content-type: application/json" http://localhost:3000/companies
# {"status":"ok","result":[{"id":1,"name":"! LTD","number":"08209948","country":"United Kingdom","url":"http://business.data.gov.uk/id/company/08209948"},{"id":2,"name":"!? LTD","number":"11399177","country":"United Kingdom","url":"http://business.data.gov.uk/id/company/11399177"}, ...

sudo snap install jq
curl -H "Content-type: application/json" http://localhost:3000/companies | jq
# {
#  "status": "ok",
#  "result": [
#    {
#      "id": 1,
#      "name": "! LTD",
#      "number": "08209948",
#      "country": "United Kingdom",
#      "url": "http://business.data.gov.uk/id/company/08209948"
#    },
#    {
#       ...

apt-get update
apt install iputils-ping

# настройка интерфейса
sudo ethtool eth0
# Управление NetworkManager через консоль
nmcli
# статус wifi
nmcli r wifi [on/off]

# /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto eth0
# iface eth0 inet dhcp
iface eth0 inet static
    address 192.168.137.1
    netmask 255.255.255.0
    network 192.168.137.0
    gateway 192.168.137.1
    dns-nameservers 8.8.8.8

# конфигурация беспроводных интерфейсов
iwconfig
# отображение информации о WiFi контроллере
lspci -vnn | grep Network