Remote access systems assigned with a public internet address will be able to initiate direct inbound and outbound sessions to the public internet. These systems will have IP addresses that start with:

  • 198.81.193
  • 204.90.115
  • 192.86.32
  • 192.86.33
  • 192.86.56

To ensure and enhance the security of the internet connections to the IBM Z® Dallas ISV Center remote access systems, IBM has blocked various ports from accepting or originating traffic. This means that the system will NOT be able to accept or originate sessions to or from the internet via an IBM Z Dallas ISV Center remote access system using the specified ports.

Blocked Ports

The following IP Ports have been blocked:

  • 20
  • 21
  • 23
  • 25
  • 135
  • 139
  • 445
  • 2240
  • 2710
  • 3391
  • 3526
  • 3531
  • 3535
  • 4662
  • 6346
  • 6348
  • 6379
  • 6881
  • 6882
  • 7881
  • 8000
  • 8001

Important Notes:

  • If you are using any of these ports, please update your application immediately so it provides services on a different port.
  • The port restrictions do not apply to remote access systems that have been assigned a private IP address on the IBM Z Dallas ISV Center VPN network.



If you have any questions, send us an email to zTech@us.ibm.com