Mantis#2032. Thank you kindly, Tyre for a patch that:

This small patch provides the required changes to populate 
the columns agentIP and agentPort in table "agents"
Tested with mysql (but should work for all supported db engines)

OpenSim/Framework/Communications/UserManagerBase.cs

@@ -28,6 +28,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Net;
 using System.Reflection;
 using System.Security.Cryptography;
 using libsecondlife;
@@ -362,6 +363,13 @@ namespace OpenSim.Framework.Communications
             // User connection
             agent.AgentOnline = true;
 
+            if (request.Params.Count > 1)
+            {
+                IPEndPoint RemoteIPEndPoint = (IPEndPoint)request.Params[1];
+                agent.AgentIP = RemoteIPEndPoint.Address.ToString();
+                agent.AgentPort = (uint)RemoteIPEndPoint.Port;
+            }
+
             // Generate sessions
             RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();
             byte[] randDataS = new byte[16];

OpenSim/Framework/Servers/BaseHttpServer.cs

@@ -380,6 +380,7 @@ namespace OpenSim.Framework.Servers
                 string methodName = xmlRprcRequest.MethodName;
                 if (methodName != null)
                 {
+                    xmlRprcRequest.Params.Add(request.RemoteIPEndPoint);
                     XmlRpcResponse xmlRpcResponse;
 
                     XmlRpcMethod method;