| Layer | Name | description |
|---|---|---|
| 1 | Physical | wires, radio waves |
| 2 | Data link | Frames (MAC addresses) |
| 3 | Networking | Logical (IP addresses) |
| 4 | Transport | Ports join/assemble data |
| 5 | Session | connection to service (ports needed) |
| 6 | Presentation | encoding/encryption of data |
| 7 | Application | wget |
MAC address 48 bits Hex
32 bits = 4,294,967,296 ~4.2 billion addresses 2^32
example: 192.168.1.51
network: 192.168.1
host: .51
most common mask /24
128 bits 2^128 example: 2607:f8b0:4023:1002::64 most common mask /64
| Protocol | Name | description |
|---|---|---|
| ARP | Address resolution | IP<-->MAC LAN only traffic |
| UDP | User Datagram Protocol | quick and efficient, not-connection based, not as reliable as TCP |
| TCP | Transmission Control Protocol | handles errors, connection/session based |
| PPP | Point to Point Protocol | older |
| EAP | Extensible Authentication Protocol | newer more common |
| Port | Service |
|---|---|
| TCP 21 | ftp |
| TCP 22 | ssh |
| TCP 23 | telnet |
| TCP 25 | SMTP Simple Mail Transfer Protocol |
| UDP 53 | DNS |
| TCP 80 | http |
| TCP 110 | POP3 Post office Protocol v3 (messages on server) |
| TCP 443 | https |
| TCP 445 | Windows Network/interprocess communication |
| TCP 3389 | Windows Remote Desktop |
| TCP 3389 | Windows Remote Desktop |
| TCP 5060,5061 | SIP - VOIP/pbx |
Private IP Addresses
| Class | Range |
|---|---|
| Class A | 10.0.0.0 - 10.255.255.255 |
| Class B | 172.16.0.0 to 172.31.255.255 |
| Class C | 192.168.0.0 to 192.168.255.255 |
|Name| what is it?| example| |--|--| |ping|check if host up|ping 192.168.0.122| |Nmap| what hosts are servers are running on your network| nmap --top ports 20 localhost|
ping 8.8.8.8 # dns.google ping 8.8.8.8 -t
ipconfig /? ipconfig/displaydns
Books/vendors Lammle Meyers "All in One" Sybex youtube: prof. Messer, NetworkChuck (https://www.youtube.com/watch?v=5WfiTHiU4x8) , CBT Nuggets, Technuggets
ss64.com # command line reference https://12ft.io/ # view search engine cached results https://automatetheboringstuff.com/ https://www.eff.org/ https://packetpushers.net/network-documentation-series-logical-diagram/