Networks make up the backbone of any connected system. For different services to be able to communicate there was a need for static port numbers to be assigned.IANA divided the range of numbers into 3 distinct groups.
well known ports(0 to 1023) ,registered ports( 1024 to 49151) & private and dynamic ports( 49152 to 65535).the majority of the port used in the cloud falls under the registered ports category.
knowing port numbers is useful when handling networking or connectivity aspects in the cloud. when dealing with VMS, load balancers, VPCs, Kubernetes, etc..you will always find ports No’s used to interconnect services. a mistake made can mean the difference between a secure and insecure app, HTTP is port 80 and HTTPS is port 443 one is secure the other is not.
| PORT NO | PROTOCOL | APPLICATION |
| 20 | TCP | FTP-DATA |
| 21 | TCP | FTP-CONTROL |
| 22 | TCP | SSH(secure shell) |
| 23 | TCP | TELNET(insecure) |
| 53 | UDP,TCP | UDP, TCP |
| 67 | UDP | DHCP SERVER |
| 68 | UDP | DHCP CLIENT |
| 69 | UDP | TFTP(trivial file transfer protocol) |
| 80 | TCP | HTTP |
| 443 | TCP | HTTPS |
| 110 | TCP | POP3(email) |
| 143 | TCP | IMAP(email) |
| 161 | UDP | SNMP |
| 8080 | TCP | UDP, TCP |
| 25 | TCP | SMTP (used to send & receive email) |
under the registered ports there are common ports like Remote Authentication Dial-In User Service (RADIUS) authentication (1812), Microsoft SQL Server (1433/1434), and the Docker REST API (2375/2376).
Knowledge of Bash is also important for a cloud professional check out these simple commands to get started.
| UNSECURE PORT | SECURE PORT |
| 25 – SMTP | 587 – SMTP USING STARTLS |
| 53- DNS | 853- DNS over TLS or DNSSEC |
| 143 – IMAP | 993- IMAP over SSL/TLS |
| 445 -SMB | 2049 -NFS over encryption |
| 389 -LDAP | 636 -LDAPS (secure) |
Did you know that the famous AWS DNS web service Route 53 actually got its name from the DNS port no 53? if you didn’t know now you do.
