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Daniel Nashed

Running Domino on IPv6

Daniel Nashed – 6 June 2021 16:26:28

In all my years working with Domino, IPv6 was never on the list of things customers asked me for. I know about very few customers using it for Domino.

Domino doesn't use IPv6 by default -- which is good because it could have some side effects in corporate environments and you want to actively decide to use it.

We had side effects with Traveler and Java which uses IPv6 automatically once enabled on the machine and we had to actively disable it on the Java side.

Enabling it is quite straightforward. There is one switch to enable it:

notes.ini TCP_EnableIPv6=1

Once you set the parameter you have to restart your Domino server! A restart of the port isn't sufficient.

There is one other change depending on your configuration.

In some cases you have to specify IPv6 addresses in the configuration. And because IPv6 contains ":" chars, you have to put IPv6 addresses in brackets like the following:


This format is also needed for internet sites.

Image:Running Domino on IPv6

For example for an inbound SMTP internet site where you have specified an IPv4 address, you have to add the IPv6 address.

Beside that the server behaves pretty much the same. In all places -- even C-API SMTP call-backs, logging, CGI variables etc, we just get the IPv6 address.

So it is quite straightforward -- specially on Linux, where you can use the same port.

Still looking into it -- specially for the edge cases, logging and API integration.

On Docker you need to enable IPv6 explicitly in


  "ipv6": true,
  "fixed-cidr-v6": "2001:db8:1::/64"

But once enabled it works like a charm on Docker as well.

What are your experiences with IPv6 on Domino?
Is anyone using it? I would be interested to hear ..


Domino IPV6 documentation

Docker IPv6 documentation

Running out of IPv addresses



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