Ports, Protocols, and IP Address Ranges for Firewalls
If you’re building or installing a firewall to protect your computer and your data, basic information about Internet configurations can come in very handy. The following tables give you the facts on IP protocols, ports, and address ranges.
Common IP Protocols
| Protocol |
Name |
| 1 |
ICMP (ping) |
| 6 |
TCP |
| 17 |
UDP |
| 47 |
GRE (PPTP) |
| 50 |
ESP (IPSec) |
| 51 |
AH (IPSec) |
Common TCP and UDP Ports
| Protocol |
Port |
Name |
| TCP |
20 |
FTP data |
| TCP |
21 |
FTP control |
| TCP |
23 |
Telnet |
| TCP |
25 |
SMTP (E-mail) |
| TCP/UDP |
53 |
DNS query |
| UDP |
67/68 |
DHCP (Dynamic IP address configuration) |
| TCP |
80 |
HTTP (Web) |
| TCP |
110 |
POP3 (E-mail) |
| TCP |
119 |
NNTP (Newsgroups) |
| TCP |
143 |
IMAP4 (E-mail) |
| TCP |
389 |
LDAP (Directory service) |
| TCP |
443 |
HTTPS (Web SSL) |
| UDP |
1701 |
L2TP (Virtual Private Networks) |
| TCP |
1723 |
PPTP (Virtual Private Networks) |
Private and Automatic IP Address Ranges
| A |
10.0.0.0 to 10.255.255.255 (10.0.0.0/8) |
| B |
172.16.0.0 to 172.31.255.255 (172.16.0.0/12) |
| C |
192.168.0.0 to 192.168.255.255 (192.168.0.0/16) |
| APIPA |
169.254.0.0 to 169.254.255.255 (169.254.0.0/16) |
