Changing a TCP or SSL port number

The following sections describe the TCP ports that IBM® Domino® services use and provide guidelines should you ever need to change these ports.

Default port for NRPC

About this task

By default, all NRPC connections use TCP port 1352. Because the Internet Assigned Number Authority (IANA) assigned Domino® this port number, non-Domino applications do not usually compete for this port.

Do not change the default NRPC port unless:

  • You can use a NAT or PAT firewall system to redirect a remote system's connection attempt.
  • You are using Domino® port mapping.
  • You create a Connection document that contains the reassigned port number.


  • To change the default NRPC port number, use the NOTES.INI setting TCPIPportname_TCPIPAddress and enter a value available on the system that runs the Domino® server.
  • TCP ports with numbers less than 5000 are reserved for application vendors. You may use any number from 1024 through 5000, as long as you don't install a new application that requires that number.
  • When setting the NOTES.INI variables for port mapping, do not include a zone in a port mapped address. The zone is only valid locally.

Default ports for Internet services

About this task

You may occasionally need to change the number of the TCP or SSL port assigned to an Internet service.


Domino® uses the default ports listed here.
Table 1. Default Ports for Internet Services


Default TCP port

Default SSL port



995 <nozeros>


143 <nozeros>

993 <nozeros>


389 <nozeros>

636 <nozeros>

SMTP inbound

25 <nozeros>

465 <nozeros>

SMTP outbound

25 <nozeros>

465 <nozeros>


80 <nozeros>

443 <nozeros>


63148 <nozeros>

63149 <nozeros>

Server Controller