mayfrost-guides/NETWORKING.md
2018-10-14 00:40:28 +00:00

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# NETWORKING
## WiFi
Use WiFi without a separate network manager with this simple guide. Needs "_dhcpcd_" or "_dhcpclient_", "_net-tools_" or "_iproute2_", "_wpa\_supplicant_", and the WiFi drivers for your wireless card (like "_iwlwifi_" and its "_ucode_"), which in part can be installed from a package usually named "_linux-firmware_", but they may not be complete (this provides "_ucode_" but not "_iwlwifi_").
__NOTE__: The "_<DEVICE_NAME>_" can be either "_wlp3s0_" or "_wlan0_". Change accordingly the following commands to suit your needs.
* Create the configuration file (as "_root_", not "_sudo_"):
`wpa_passphrase <NETWORK_NAME> <PASSWORD> > /etc/wpa_supplicant.conf`
* Delete non hashed password from "_/etc/wpa_supplicant.conf_", but not the hashed one.
Each time you need to connect type the following command (as "_root_" or with "_sudo_"):
* __EXAMPLE 1__: With "_net-tools_" and "_dhcpcd_":
```
ifconfig <DEVICE_NAME> down
ifconfig <DEVICE_NAME> up
wpa_supplicant -B -i<DEVICE_NAME> -c /etc/wpa_supplicant.conf -Dwext
dhcpcd <DEVICE_NAME>
```
* __EXAMPLE 2__: With "_iproute2_" and "_dhclient_":
```
ip link set <DEVICE_NAME> down
ip link set <DEVICE_NAME> up
wpa_supplicant -B -i<DEVICE_NAME> -c /etc/wpa_supplicant.conf -Dwext
dhclient <DEVICE_NAME>
```
You can save either example in a script to activate the Wi-Fi whenever you want.
* Note: As an educational tip, the name of a network is also called "_SSID_" in other places.
## Next
### ufw
* Show status
`sudo ufw status`
* Enable firewall
`sudo ufw enable`
* Disable firewall
`sudo ufw disable`
* Deny all by default
`sudo ufw default deny`
* Allow all by default
`sudo ufw default allow`
* Allow everything for specific port by default
`sudo ufw allow PORT_NUMBER`
* Delete a rule
`sudo ufw delete allow PORT_NUMBER`
* Allow everything for a specific address
`sudo ufw allow from IP_ADDRESS`
* Allow a specific port for a specific address
`sudo ufw allow from IP_ADDRESS to any port PORT_NUMBER`
### tcpdump
* dump all
`sudo tcpdump`
* dump 5 packets
`sudo tcpdump -c 5`
* dump in ASCii format
`sudo tcpdump -A`
* dump in hexadecimal format
`sudo tcpdump -xx`
* dump from an specific interface
`sudo tcpdump -i INTERFACE_NAME`
* dump from a specific port
`sudo tcpdump port PORT_NUMBER`
* dump 5 packets in hexadecimal from an specific interface and a specific port
`sudo tcpdump -c 5 -xx -i INTERFACE port PORT_NUMBER`
### netstat
* show routing table, including gateway
`netstat -nr`
* show all ports
`netstat -tulpn`
* show network usage of devices
`netstat -i`
* show active connections
`netstat -ta`
* show active connections, but show ip addresses instead
`netstat -tan`
### traceroute
* show which route your connection takes between your computer to the destination
`traceroute WEBNAME_OR_IP`
### nmap
* scan a specific ip address (including devices)
`nmap IP_NUMBER`
* scan a specific website
`nmap WEBSITE_NAME`
* scan a specific ip address (including devices) with more information
`nmap -v IP_NUMBER`
* scan two ip address (including devices), 192.168.0.1 and 192.168.0.54
`nmap 192.168.0.1,54`
* scan a range of ip address (including devices), from 192.168.0.1 to 192.168.0.100
`nmap 192.168.0.1-100`
* scan all ip address (including devices) from network 192.168.0.0
`nmap 192.168.0.*`
* scan address from a file
`nmap -il <FILE>`
* scan address and identify OS and running services
`nmap -A IP_NUMBER`
* check if target is up
`nmap -sP IP_NUMBER`
* check reason for services states
`nmap --reason IP_NUMBER`
* show host interfaces
`nmap --iflist IP_NUMBER`
### SSH
* login to remote host
`ssh ADDRESS`
* login to remote host as user USER
`ssh USER@ADDRESS`
* set ssh server configuration in /etc/ssh/sshd_config
```
Port 22 # default port
PermitRootLogin without-password # change "without-password" to "no"
AllowUsers USER_NAME # by allowing a specific user it restricts the others
```
* restart "ssh" service to activate changes
## /etc/network/interfaces
```
# use last 8 octets for hosts
255.255.255.0
```