The ip command has replaced the deprecated ifconfig command.
Physical Layer:
ip link
ip addr
ip addr show dev [interface]
ip addr add [IP_Address/Mask] dev [interface]
ip addr del [IP_Address/Mask] dev [interface]
sudo ip link set [interface] up
sudo ip link set [interface] down
ip route
All "changes" using the ip command are applied for the current session and are not reboot persistent. This tool is used to preform temporary network assignments for transferring logs and/or data in emergency situations.
| ifconfig | = | ip addr |
| route | = | ip route |
| arp | = | ip neigh |
| netstat | = | ss |
There are three IP address spaces set aside for private networks:
| Class | From | To |
| A | 10.0.0.0 | 10.255.255.255 |
| B | 172.16.0.0 | 172.31.255.255 |
| C | 192.168.0.0 | 192.168.255.255 |
The Raspberry Pi OS is based off of the Linux Debian distribution. In Debian 8 (jessie), systemd became the system and service manager.
A few days later (2015/05/050, Raspian Jessie was introduced. With it came systemd, a Dynamic Host Configuration Protocol client (dhcpcd), and network configurations files: /etc/dhcpcd.conf and /etc/wpa_supplicant/wpa_supplicant.conf.
Before this the network configuration file(s) was /etc/network/interfaces.This change made a large number of tutorials obsolete. Furthermore, because /etc/netowrk/interaces is still present, there is still a lot of confusion.
https://wiki.debian.org/systemd
https://wiki.debian.org/NetworkConfiguration
Debian 11 includes its own networ .service, dhcpcd (dynamic host configuration protocl client deamon) that manages network interfaces. By default, it is enabled.
Debian 10 used a different network service manager, ifupdown package, and configuration was done in /etc/network/interfaces.
Debian includes an alternate network service manager, systemd-networkd.service. By default, it is not enabled.
its own network.service to manage the Since, the release of Debian 10 (bullseye) in October 2001, the Raspberry Pi OS has included a Dynamic Host Configuration Protocol (dhcp) client (dhcpcd - client daemon). A hdcp client communicates with a dhcp server (usually the router), and obtains IP addresses from the dhcp server. However, a dhcp client can request static IP addresses from the server. This is done by modifying the /etc/dhcpcd.conf file:
The best way allocate a static IP for an interface is at the hdcp server (router).
modify the /etc/dhcpcd.conf file:
interface eth0
static ip_address=192.168.0.4/24
static routers=192.168.0.254
static domain_name_servers=192.168.0.254 8.8.8.8
Note that the static ip_address also include the subnet mask
The Raspberry Pi OS does not use systemd-networkd to manage networking. To use systemd-networkd, the hdcp client and other packages must be removed and the systemd-networkd package must be installed.
The Raspberry Pi OS does not use NetworkManger, which was introduced by Red Hat in 2004.
The Raspberry Pi OS is based off of the Linux Debian distribution.
| Debian | Code Name | Release Date |
| 11 | bullseye | 2021/09/14 |
| 10 | buster | 2019/07/06 |
| 09 | stretch | 2017/06/17 |
| 08 | jessie | 2015/04/26 |
| 7 | wheezy | 2013/05/04 |
| TCP | Transmission Control Protocol |
| UDP | User Datagram Protocol |
| ICMP | Internet Control Message Protocol |
The Internet Control Message Protocol (ICMP) is a network layer protocol used by network devices to diagnose network communication issues. ICMP is mainly used to determine whether or not data is reaching its intended destination in a timely manner. Commonly, the ICMP protocol is used on network devices, such as routers. ICMP is crucial for error reporting and testing, but it can also be used in distributed denial-of-service (DDoS) attacks.
To investigate if a Raspberry Pi 4B-8GB could replace a commercial router (Apple Extreme 802.11ac), a 5.06 G Byte folder, Electrical-Forensics, was copied from my Synology NAS (2020) to my MacBook Pro (Late 2013).
| Radio | Source | Destination | Time |
| RPi Internal | Synologic NAS | Apple MacBook Pro | 13:18 |
| RPi External | Synologic NAS | Apple MacBook Pro | 7:30 |
| Apple Extreme | Synologic NAS | Apple MacBook Pro | 1::34 |
The bottom line is, it's too slow for large data transfers, but it is probably adequate for surfing the web.
| SSID | Service Set ID | Name of the Network |
| BSSID | Basic Service Set ID | MAC address of the AP |
| WEP | Wired Equivalent Privacy | 1999 |
| WPA | Wireless Protected Access | 2003 |
| WPA2 | Wireless Protected Access | Version 2 -2004 |
| WPA3 | Wireless Protected Access | Version 3 -2018 |
| PSK | Pre-Shared Key | Authentication Method |
| TKIP | Temporal Key Inegrity Protocol | encription Keys for wireless clients |
| CMMP | Counter Mode MAC Protocol | default encription Protocol for WPA-2 |
| SAE | Simultaneous Authentication of Equals | default encription Protocol for WPA-3 |
| PMF | Protected Management Frames | WPA-3 |
| AES | Advanced Encryption Standard | symmetric encryption - shared key |
| RSA | Rivest-Shamir-Adleman | asymmetric encryption - public and private keys |
| RSN | Robust Security Network |
In a Wireless Networks, the user has to be authenicated and the data encripted. For personal networks, the authentication is passphrase-based.
| PSK | Pre-Shared Key | |
| TKIP | Temporal Key Inegrity Protocol | |
| CMMP | Counter Mode MAC Protocol | default encription Protocol for WPA-2 |
TKIP, dynamically generates a new key for each packet of data.
