# Ports

| Protocol | Port number | Transport Layer |
| -------- | -------- | -------- |
| DNS | 53 | UDP |
| DHCP |68 | UDP
| HTTP | 80 | TCP |
| HTTPS | 443 | TCP |
| SMTP | 25 | TCP |
| POP3 | 110 | TCP |
| IMAP4 | 143 | TCP |
| FTP |20/21| TCP |
| TFTP | 69 | UDP |
| TELNET |23 | TCP |
| SSH | 22 | TCP|
| SNMP | 161 | UDP |
| SIP | |
| SSH | 22| TCP |
| HTTP | 80 | TCP |
| HTTPS | 443 | TCP |