--- a/agent/core/src/main/java/com/redhat/thermostat/agent/Agent.java	Wed Nov 16 17:51:01 2016 +0100
+++ b/agent/core/src/main/java/com/redhat/thermostat/agent/Agent.java	Mon Nov 14 15:19:00 2016 +0100
@@ -159,11 +159,7 @@
         agentInfo.setStartTime(config.getStartTime());
         agentInfo.setAlive(true);
         HostPortPair hostPort = config.getConfigListenAddress();
-        String host = hostPort.getHost();
-        if (host.indexOf(":") != -1) {
-            host = "[" + host + "]";
-        }
-        agentInfo.setConfigListenAddress(String.format("%s:%d", host, hostPort.getPort()));
+        agentInfo.setConfigListenAddress(hostPort.toExternalForm());
         return agentInfo;
     }
 

--- a/common/core/src/main/java/com/redhat/thermostat/common/utils/HostPortPair.java	Wed Nov 16 17:51:01 2016 +0100
+++ b/common/core/src/main/java/com/redhat/thermostat/common/utils/HostPortPair.java	Mon Nov 14 15:19:00 2016 +0100
@@ -36,13 +36,25 @@
 
 package com.redhat.thermostat.common.utils;
 
+/**
+ * Model class for a hostname/port pair.
+ * 
+ * @see HostPortsParser
+ */
 public class HostPortPair {
-    private String host;
-    private int port;
+    
+    private final String host;
+    private final int port;
+    private final boolean isIPv6;
     
     public HostPortPair(String host, int port) {
+        this(host, port, false);
+    }
+    
+    HostPortPair(String host, int port, boolean isIPv6) {
         this.host = host;
         this.port = port;
+        this.isIPv6 = isIPv6;
     }
 
     public String getHost() {
@@ -52,5 +64,17 @@
     public int getPort() {
         return port;
     }
+    
+    /**
+     * 
+     * @return A parseable external form of this host/port pair. Examples:
+     *         {@code host.example.com:12345} {@code [::1]:123}
+     */
+    public String toExternalForm() {
+        String myHost = host;
+        if (isIPv6) {
+            myHost = "[" + myHost + "]";
+        }
+        return String.format("%s:%d", myHost, port);
+    }
 }
-

--- a/common/core/src/main/java/com/redhat/thermostat/common/utils/HostPortsParser.java	Wed Nov 16 17:51:01 2016 +0100
+++ b/common/core/src/main/java/com/redhat/thermostat/common/utils/HostPortsParser.java	Mon Nov 14 15:19:00 2016 +0100
@@ -110,7 +110,7 @@
                 } catch (NumberFormatException e) {
                     throw formatException;
                 }
-                ipPorts.add(new HostPortPair(ipPortPair.substring(idxLParen + 1, idxRparen), port));
+                ipPorts.add(new HostPortPair(ipPortPair.substring(idxLParen + 1, idxRparen), port, true));
             }
         }
     }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common/core/src/test/java/com/redhat/thermostat/common/utils/HostPortPairTest.java	Mon Nov 14 15:19:00 2016 +0100
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2012-2016 Red Hat, Inc.
+ *
+ * This file is part of Thermostat.
+ *
+ * Thermostat is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2, or (at your
+ * option) any later version.
+ *
+ * Thermostat is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Thermostat; see the file COPYING.  If not see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Linking this code with other modules is making a combined work
+ * based on this code.  Thus, the terms and conditions of the GNU
+ * General Public License cover the whole combination.
+ *
+ * As a special exception, the copyright holders of this code give
+ * you permission to link this code with independent modules to
+ * produce an executable, regardless of the license terms of these
+ * independent modules, and to copy and distribute the resulting
+ * executable under terms of your choice, provided that you also
+ * meet, for each linked independent module, the terms and conditions
+ * of the license of that module.  An independent module is a module
+ * which is not derived from or based on this code.  If you modify
+ * this code, you may extend this exception to your version of the
+ * library, but you are not obligated to do so.  If you do not wish
+ * to do so, delete this exception statement from your version.
+ */
+
+package com.redhat.thermostat.common.utils;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class HostPortPairTest {
+
+    @Test
+    public void testExternalFormIPv4() {
+        HostPortPair pair = new HostPortPair("foo.example.com", 33);
+        assertEquals("foo.example.com:33", pair.toExternalForm());
+        pair = new HostPortPair("127.0.0.1", 90);
+        assertEquals("127.0.0.1:90", pair.toExternalForm());
+    }
+    
+    @Test
+    public void testExternalFormIPv6() {
+        HostPortPair pair = new HostPortPair("::1", 999, true);
+        assertEquals("[::1]:999", pair.toExternalForm());
+        pair = new HostPortPair("fe80::565a:be2e:e9d3:ba1b", 12000, true);
+        assertEquals("[fe80::565a:be2e:e9d3:ba1b]:12000", pair.toExternalForm());
+    }
+}

--- a/common/core/src/test/java/com/redhat/thermostat/common/utils/HostPortsParserTest.java	Wed Nov 16 17:51:01 2016 +0100
+++ b/common/core/src/test/java/com/redhat/thermostat/common/utils/HostPortsParserTest.java	Mon Nov 14 15:19:00 2016 +0100
@@ -59,6 +59,7 @@
         assertEquals("127.0.0.1", ipPorts.get(0).getHost());
         assertEquals(9999, (long) ipPorts.get(1).getPort());
         assertEquals("127.0.0.1", ipPorts.get(1).getHost());
+        assertEquals("127.0.0.1:8080", ipPorts.get(0).toExternalForm());
     }
     
     @Test
@@ -70,6 +71,7 @@
         assertEquals(2, ipPorts.size());
         assertEquals(8080, (long) ipPorts.get(0).getPort());
         assertEquals("somehost.example.com", ipPorts.get(0).getHost());
+        assertEquals("somehost.example.com:8080", ipPorts.get(0).toExternalForm());
         assertEquals(9999, (long) ipPorts.get(1).getPort());
         assertEquals("host2.example.com", ipPorts.get(1).getHost());
         parser = new HostPortsParser(
@@ -89,9 +91,29 @@
         assertEquals(2, ipPorts.size());
         assertEquals(8001, (long) ipPorts.get(0).getPort());
         assertEquals("1fff:0:a88:85a3::ac1f", ipPorts.get(0).getHost());
+        assertEquals("[1fff:0:a88:85a3::ac1f]:8001", ipPorts.get(0).toExternalForm());
         assertEquals(8001, (long) ipPorts.get(1).getPort());
         assertEquals("1fff:0:a88:85a3::ac2f", ipPorts.get(1).getHost());
     }
+    
+    @Test
+    public void canParseExternalizedPair() {
+        HostPortPair original = new HostPortPair("foo.example.com", 999, false);
+        doExternalizedPairTest(original);
+        original = new HostPortPair("::1", 38, true);
+        doExternalizedPairTest(original);
+        original = new HostPortPair("127.0.0.1", 8000);
+        doExternalizedPairTest(original);
+    }
+    
+    private void doExternalizedPairTest(HostPortPair original) {
+        HostPortsParser parser = new HostPortsParser(original.toExternalForm());
+        parser.parse();
+        HostPortPair newPair = parser.getHostsPorts().get(0);
+        assertEquals(original.getHost(), newPair.getHost());
+        assertEquals(original.getPort(), newPair.getPort());
+        assertEquals(original.toExternalForm(), newPair.toExternalForm());
+    }
 
     @Test
     public void failsParsingInvalidString() {