Appendix C. Common Application Ports
Table C-1. Common application source and destination ports
|
Service |
Protocol |
Source port (on client unless specified) |
Destination port (on server unless specified) |
|---|---|---|---|
|
DNS |
UDP |
53 > 1023 |
53 |
|
DNS (for zone transfers and for large queries in presence of large packet loss) |
TCP |
> 1023 |
53 |
|
FTP (control connection) |
TCP |
> 1023 |
21 |
|
FTP (data connection) |
TCP |
20 (from server) |
> 1023 (to client) |
|
FTP PASV data connection |
TCP |
> 1023 |
20 |
|
FTP PASV data connection as implemented by many browsers |
TCP |
> 1023 |
> 1023 |
|
IDENT (often used by mailers) |
TCP |
> 1023 |
113 |
|
Netbios name service |
UDP |
137 > 1023 |
137 |
|
Netbios datagram service |
UDP |
138 > 1023 |
138 |
|
Netbios file sharing |
TCP |
> 1023 |
139 |
|
NNTP (News) |
TCP |
> 1023 |
119 |
|
NTP (Network Time Protocol) |
UDP |
123 |
123 |
|
POP3 |
TCP |
> 1023 |
110 |
|
REXEC |
TCP |
> 1023 |
512 |
|
RLOGIN |
TCP |
< 1024 |
513 |
|
RSH |
TCP |
< 1024 |
514 |
|
SMTP |
TCP |
> 1023 |
25 |
|
SNMP |
UDP |
> 1023 |
161 |
|
SOCKS |
TCP |
> 1023 |
1080 |
|
Squid Proxy |
TCP |
> 1023 |
3128 |
|
SSH (Secure Shell) |
TCP |
> 1023 |
22 |
|
SSL |
TCP |
> 1023 |
443 |
|
Syslog |
UDP |
> 1023 |
514 |
|
TACACS |
UDP |
49 |
49 |
|
Telnet |
TCP |
> 1023 |
23 |
|
TFTP |
UDP |
> 1023 |
69 |
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