Migrate Remote IP Addresses to a New Relay Connector

In many Exchange transition projects, there is a need to migrate some receive connector settings used in an existing SMTP relay connector to the new servers being stood up in preparation for decommissioning legacy servers.
 
Also, in most cases, there are several remote IP addresses assigned to existing relay connectors that need to be assigned to the new receive connector. Imagine trying to manually copy and add each address … Not fun!
 
In this example, I will “migrate” the remote IP addresses of an existing receive connector (configured for relay) on Exchange 2013 server to a new “relay” connector on Exchange 2016. The server name EX1 represents Exchange 2013 and EX2 represents Exchange 2016.
 
GATHER BASIC CONNECTOR INFO
First, using the Exchange Management Shell (EMS) from the Exchange 2013 server, I will gather some general information regarding all of the existing receive connectors in the organization.
 

Get-ReceiveConnector | ft -auto

Select all Open in new window

 
Running get-receiveconnector displays all of the existing receive connectors for both server. The one I am targeting is “EX1\Relay EX1”; the SMTP relay connector on the Exchange 2013 server.
 

Identity                         Bindings                   Enabled
                      --------                         --------                   -------
                      EX1\Default EX1                  {0.0.0.0:2525, [::]:2525}  True
                      EX1\Client Proxy EX1             {[::]:465, 0.0.0.0:465}    True
                      EX1\Default Frontend EX1         {[::]:25, 0.0.0.0:25}      True
                      EX1\Outbound Proxy Frontend EX1  {[::]:717, 0.0.0.0:717}    True
                      EX1\Client Frontend EX1          {[::]:587, 0.0.0.0:587}    True
                      EX1\Relay EX1                    {0.0.0.0:25}               True
                      EX2\Default EX2                  {0.0.0.0:2525, [::]:2525}  True
                      EX2\Client Proxy EX2             {[::]:465, 0.0.0.0:465}    True
                      EX2\Default Frontend EX2         {[::]:25, 0.0.0.0:25}      True
                      EX2\Outbound Proxy Frontend EX2  {[::]:717, 0.0.0.0:717}    True
                      EX2\Client Frontend EX2          {[::]:587, 0.0.0.0:587}    True

Select all Open in new window

 
I need to get specific remote IP address information regarding the relay connector on EX1, so, I run the following command to provide me with a visual display of the addresses I intend to migrate to a new relay connector on EX2.
 

Get-ReceiveConnector "EX1\Relay EX1" | fl RemoteIPRanges

Select all Open in new window

 
The remote IP addresses are displayed, however, the list is truncated…
 

RemoteIPRanges : {172.16.20.5, 172.16.162.50, 172.16.104.5, 10.88.162.9, 10.88.162.58, 
                      10.88.162.26, 10.88.162.24, 10.88.162.237, 10.88.162.2, 10.88.162.19, 10.88.162.18, 
                      10.88.162.15, 10.87.104.29, 10.87.104.26, 10.85.99.96, 10.85.99.36...}

Select all Open in new window

 
DISPLAY LIMITATION
The fact that all of the addresses aren’t displayed does me no good. But, I can make a modification to how values are displayed. I now run the following two commands to check, and set, the display limit.
 
I’ll start with this command…
 

$FormatEnumerationLimit

Select all Open in new window

 
The default value is 16. What that means is that any command will display a limit of 16 values. So, if I have more than 16 IP addresses (or ranges) assigned to my connector, running the ‘Get-ReceiveConnector’ command to reveal the remote IP addresses will display up to only 16 values (or IP addresses).
 
If I want to see more of the values, I can run the $FormatEnumerationLimit with a larger value like 20 or 30 or whatever I wish. However, I want to see all of the values displayed. Therefore, I run the following command which allows for an unlimited number of values to be displayed.
 

$FormatEnumerationLimit =-1

Select all Open in new window

 
Now, when I run this command again…
 

Get-ReceiveConnector "EX1\Relay EX1" | fl RemoteIPRanges

Select all Open in new window

 
The full list of assigned IP addresses (including subnets and ranges) is displayed.
 

RemoteIPRanges : {172.16.20.5, 172.16.162.50, 172.16.104.5, 10.88.162.9, 10.88.162.58, 
                      10.88.162.26, 10.88.162.24, 10.88.162.237, 10.88.162.2, 10.88.162.19, 10.88.162.18, 10.88.162.15, 
                      10.87.104.29, 10.87.104.26, 10.85.99.96, 10.85.99.36, 10.85.99.25, 10.83.7.87, 10.83.7.61, 
                      10.83.7.60, 10.83.7.54, 10.83.7.43, 10.83.7.41, 10.83.7.237, 10.83.7.233, 10.83.7.18, 
                      10.83.7.147, 10.81.26.101, 10.0.0.0/24, 192.168.100.94-192.168.100.104, 10.10.10.151}

Select all Open in new window

 
CREATE CONNECTOR AND ADD REMOTE IP ADDRESSES
Now that I can visually see all of the remote IP addresses, I could copy and paste them manually into a new receive connector but I don’t want to. Instead, I will create a new receive connector (for relay) via the EMS (still from the 2013 server) and add the existing remote IP addresses from the relay connector on EX1 to the new connector on EX2.
 
I run this command because I need to gather settings into a variable ($RecvConn) from the existing relay connector on EX1.
 

$RecvConn = Get-ReceiveConnector "EX1\Relay EX1"

Select all Open in new window

 
Then, I create the new relay connector (Relay EX2) with this command by populating the RemoteIPRanges parameter with the values gather from “Relay EX1” in the previous command, and adding ‘AnonymousUsers’ to the permission group.
 

New-ReceiveConnector -Name "Relay EX2" -RemoteIPRanges $RecvConn.RemoteIPRanges -Bindings @('0.0.0.0:25') -Usage "Custom" -Server "EX2" -TransportRole "FrontendTransport" -PermissionGroups "AnonymousUsers"

Select all Open in new window

 
Finally, we complete the new relay connector by setting it to accept anonymous messages from the remote IP addresses.
 

Get-ReceiveConnector "EX2\Relay EX2" | Add-ADPermission -User 'NT AUTHORITY\Anonymous Logon' -ExtendedRights MS-Exch-SMTP-Accept-Any-Recipient

Select all Open in new window

 
CONCLUSION
After the new relay connector is created, I like to thoroughly test it to ensure it functions for my needs. For me, I prefer this method to others because it is relatively simple to implement and get working in a short amount of time.
 
Good luck and have fun!
 
Reference(s):

• How to Add Remote IP Addresses to Existing Receive Connectors
• How to Prevent Truncation of Long Output in Exchange Management Shell
• How to Configure Exchange Server 2016 for SMTP Application Relay
• How to Configure a Relay Connector in Exchange Server 2013
• How to Configure a Relay Connector for Exchange Server 2010