Understanding IP Address Spaces and Common Ports
Understanding IP Address Spaces
Private IPv4 Address Spaces
The following table lists the private IPv4 address spaces:
| Address Block | Description |
| 127.0.0.0/8 | Loopback |
| 192.168.0.0/16 | Private Network |
| 10.0.0.0/8 | Private Network |
| 100.64.0.0/10 | Shared address space[4] carrier-grade NAT. |
| 172.16.0.0/12 | Private Network (172.16.0.0–172.31.255.255) |
Special Use IPv4 Addresses
These addresses are reserved for specific purposes:
| Address Block | Description |
| 224.0.0.0/4 | IP multicast.[10] (Former Class D network.) |
| 240.0.0.0/4 | Reserved for future use.[12] (Former Class E network.) |
Special Use IPv6 Addresses
These addresses are designated for specific functions in IPv6:
| Address Block | Description |
| fc00::/7 | Unique local address[19] |
| fe80::/64 from fe80::/10 | Link-local address |
| ff00::/8 | Multicast address |
| ::ffff:0:0/96 | IPv4-mapped addresses |
| ::ffff:0:0:0/96 | IPv4 translated addresses |
Commonly Used Network Ports
Here is a list of commonly used network ports and their associated protocols:
- 20: FTP (File Transfer Protocol) Data
- 21: FTP Control
- 22: SSH (Secure Shell)
- 23: Telnet
- 25: SMTP (Simple Mail Transfer Protocol)
- 49: TACACS+
- 53: DNS (Domain Name System)
- 67, 68: DHCP (Dynamic Host Configuration Protocol), BOOTP (Bootstrap Protocol)
- 69: TFTP (Trivial File Transfer Protocol)
- 80: HTTP (Hypertext Transfer Protocol)
- 110: POP3 (Post Office Protocol version 3)
- 116: NNTP (Network News Transfer Protocol)
- 123: NTP (Network Time Protocol)
- 137: NetBIOS Name Service
- 153: SGMP (Simple Gateway Monitoring Protocol)
- 161/162: SNMP (Simple Network Management Protocol) / SNMP Trap
- 179: BGP (Border Gateway Protocol)
- 319/320: Precision Time Protocol (PTP)
- 389: LDAP (Lightweight Directory Access Protocol)
- 443: HTTPS (Hypertext Transfer Protocol Secure)
- 546/547: DHCPv6 Client/Server
- 554: RTSP (Real Time Streaming Protocol)
- 830: NETCONF (Network Configuration Protocol)
- 1701/1707: L2F (Layer 2 Forwarding) / L2TP (Layer 2 Tunneling Protocol)
- 1723: PPTP (Point-to-Point Tunneling Protocol)
- 1812, 1813: RADIUS Authentication / Accounting
- 1985: HSRP (Hot Standby Router Protocol)
- 2083: RadSec (RADIUS over TLS)
- 2375-2377: Docker Plain/SSL/Swarm
802.11 MAC Frame Types
The following table details 802.11 MAC frame types and subtypes:
| B3..B2 | Description | Subtype B7..B4 | Subtype Description |
| 00 | Management | 0000 | Association Request |
| 00 | Management | 0001 | Association Response |
| 00 | Management | 0010 | Reassociation Request |
| 00 | Management | 0011 | Reassociation Response |
| 00 | Management | 0100 | Probe Request |
| 00 | Management | 0101 | Probe Response |
| 00 | Management | 0110 | Timing Advertisement |
| 00 | Management | 0111 | Reserved |
| 00 | Management | 1000 | Beacon |
| 00 | Management | 1001 | ATIM |
| 00 | Management | 1010 | Disassociation |
| 00 | Management | 1011 | Authentication |
| 00 | Management | 1100 | Deauthentication |
| 00 | Management | 1101 | Action |
| 00 | Management | 1110 | Action No Ack (NACK) |
| 00 | Management | 1111 | Reserved |
| 01 | Control | 0000-0001 | Reserved |
| 01 | Control | 0010 | Trigger[3] |
| 01 | Control | 0011 | TACK |
| 01 | Control | 0100 | Beamforming Report Poll |
| 01 | Control | 0101 | VHT/HE NDP Announcement |
| 01 | Control | 0110 | Control Frame Extension |
| 01 | Control | 0111 | Control Wrapper |
| 01 | Control | 1000 | Block Ack Request (BAR) |
| 01 | Control | 1001 | Block Ack (BA) |
| 01 | Control | 1010 | PS-Poll |
| 01 | Control | 1011 | RTS |
| 01 | Control | 1100 | CTS |
| 01 | Control | 1101 | ACK |
| 01 | Control | 1110 | CF-End |
| 01 | Control | 1111 | CF-End + CF-ACK |
| 10 | Data | 0000 | Data |
| 10 | Data | 0001-0011 | Reserved |
| 10 | Data | 0100 | Null (no data) |
| 10 | Data | 0101-0111 | Reserved |
| 10 | Data | 1000 | QoS Data |
| 10 | Data | 1001 | QoS Data + CF-ACK |
| 10 | Data | 1010 | QoS Data + CF-Poll |
| 10 | Data | 1011 | QoS Data + CF-ACK + CF-Poll |
| 10 | Data | 1100 | QoS Null (no data) |
| 10 | Data | 1101 | Reserved |
| 10 | Data | 1110 | QoS CF-Poll (no data) |
| 10 | Data | 1111 | QoS CF-ACK + CF-Poll (no data) |
| 11 | Extension | 0000 | DMG Beacon |
| 11 | Extension | 0001 | S1G Beacon |
| 11 | Extension | 0010-1111 | Reserved |
