Default Port Assignments for Common Services and Tasks

Table under lists port numbers for common applications. If you aren't sure which port numbers your software uses, seek advice from the application's manual or touch the technical assist team. Alternatively, you could use a protocol analyzer, along with Network Monitor, to observe network site visitors to decide the port numbers used.

Service Name or Task UDP TCP
Web servers, HTTP, and Internet Information Services (IIS) 80
HTTP- Secure Sockets Layer (SSL) 443
DNS client-to-server lookup (varies) 53 53
DHCP client 67
File and printer sharing 137 139,445
FTP-control 21
FTP-data 20
Internet Relay Chat (IRC) 6667
Microsoft Office Outlook (see POP3, IMAP, and SMTP for ports)
Internet Mail Access Protocol (IMAP) 143
IMAP (SSL) 993
LDAP 389
LDAP (SSL) 636
Message Transfer Agent (MTA) - X.four hundred over TCP/IP 102
POP3 110
POP3 (SSL) 995
RPC endpoint mapper 135
SMTP 25
Network News Transfer Protocol (NNTP) 119
NNTP (SSL) 563
POP3 110
POP3 (SSL) 995
SNMP 161
SNMP Trap 162
SQL Server 1433
Telnet 23
Terminal Server and Remote Desktop 3389
Point-to-Point Tunneling Protocol (PPTP) 1723
Joining an AD DS domain (See the section titled "How to Troubleshoot Joining or Logging on to a Domain" later on this tutorial for more data.)
After identifying the port number, step one in troubleshooting the utility connectivity problem is to decide whether communications are successful using that port.

If it's far a TCP port, you can use PortQry, Test TCP, or Telnet. Of those 3 tools, Telnet is the least flexible, but it is the only device protected with Windows (however note that it is not mounted by using default). For more records about Telnet, including a way to installation it, see the section titled "Telnet Client" earlier in this tutorial. Troubleshoot Your Network

To check a TCP port with Telnet, run the following command.

Telnet hostname_or_address TCP_port
For example, to decide whether you can connect with the Web server at www.Sourcedaddy.Com (which makes use of port 80), you would run the subsequent command.

Telnet www.Sourcedaddy.Com 80
If the command prompt clears or in case you get hold of text from the faraway service, you have effectively hooked up a connection. Close the command set off to cancel Telnet. This suggests that you can hook up with the server; therefore, the server software is listening for incoming connections and no firewall is blocking your visitors. Instead of troubleshooting the hassle as a connectivity issue, you should keep in mind application-stage issues, including: