Last modified at 11/2/2013 9:10 PM by Koen Zomers

​Microsoft Exchange 2010 supports IPv6. However enabling it for IPv6 through the Exchange Management Console (EMC) is not completely intuitive. This article will show how to do this. The procedure is the same for a Client Access Role (CAS) server as well as for an Edge Role server. It is also the same when editing a current receive connector or creating a new one.

When creating a new Receive Connector in Exchange 2010, you will notice that by default it shows that it will bind to all available IPv4 addresses only:

Exchange2010-IPv6-NewReceiveConnectorAddBinding.png

In the Add Receive Connector Binding dialog you will notice the option Use all IP addresses available on this server. This however only represents IPv4 addresses. Thus when adding a binding with this option, it will result in the above screenshot.

Exchange2010-IPv6-NewReceiveConnectorAddBinding-Dialog.png

And yes, it only binds to IPv4:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-NetstatBefore.png

So if we want to bind to IPv6 as well, what do we do? We add the following binding:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-DialogIPv6Bindall.png

Note the two colons in the IP address binding field. This will result in the IPv6 binding to be added:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-IPv6Added.png

And it to bind to all available IPv6 addresses indeed:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-NetstatAfterAll.png

Not really intuitive is it?

We could also bind to a specific IPv6 instead:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-DialogIPv6BindSpecific.png

This will result in a binding specific to this IPv6 address:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-NetstatAfterSpecific.png

But wait, there's one more thing! You still must allow IPv6 addresses to connect your Exchange 2010 server or your requests will get cut off directly with the following message:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-IPv6Denied.png

This is because by default only IPv4 is allowed to connect to Exchange 2010 as shown in the Receive Connector properties:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-AcceptIPv4Only.png

So what we'll do is add another entry in which we specify the IPv6 address(es) that we allow to connect to your Exchange 2010 server. Use the CIDR format for this. In case you want any IPv6 address to connect, specify:

::-ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff

Exchange2010-IPv6-NewReceiveConnectorAddBinding-IPv6AddRange.png

And now it will show that also all IPv6 addresses are allowed to connect to our Exchange server:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-IPv6RangeAdded.png

And if we verify this by telnetting to the IPv6 address of the server on port 25, we'll see that now it does accept our connection:

Exchange2010-IPv6-NewReceiveConnectorAddBinding-IPv6TelnetTest.png