Matching Pairs Ports and ProtocolsOnline version Match the port number to the protocol name. by J L 1 SMTP 2 HTTPS 3 DHCP 4 IMAP over SSL 5 POP3 over SSL 6 TFTP 7 SNMP 8 RDP 9 LDAP 10 POP3 11 SSH 12 NTP 13 FTP 14 IMAP 15 NetBIOS TCP/IP 16 DNS 17 HTTP 18 TELNET 3389 143 443 80 25 993 22 20/21 67/68 110 995 69 389 23 137,138,139 53 161/162 123