diff --git a/Spec/RealtimeClientConnection.swift b/Spec/RealtimeClientConnection.swift
index 6ca4c6fba..7daa09af6 100644
--- a/Spec/RealtimeClientConnection.swift
+++ b/Spec/RealtimeClientConnection.swift
@@ -2489,6 +2489,46 @@ class RealtimeClientConnection: QuickSpec {
                     expect(NSRegularExpression.match(urlConnections[0].absoluteString, pattern: "//realtime.ably.io")).to(beTrue())
                 }
 
+                // RTN17a
+                pending("every connection is first attempted to the primary host realtime.ably.io") {
+                    let options = ARTClientOptions(key: "xxxx:xxxx")
+                    options.autoConnect = false
+                    let client = ARTRealtime(options: options)
+                    let channel = client.channels.get("test")
+
+                    client.setTransportClass(TestProxyTransport.self)
+                    TestProxyTransport.network = .HostUnreachable
+                    defer { TestProxyTransport.network = nil }
+
+                    var urlConnections = [NSURL]()
+                    TestProxyTransport.networkConnectEvent = { url in
+                        urlConnections.append(url)
+                        TestProxyTransport.network = nil
+                    }
+
+                    client.connect()
+                    defer { client.close() }
+
+                    waitUntil(timeout: testTimeout) { done in
+                        channel.publish(nil, data: "message") { error in
+                            done()
+                        }
+                    }
+
+                    client.connect()
+
+                    waitUntil(timeout: testTimeout) { done in
+                        channel.publish(nil, data: "message") { error in
+                            done()
+                        }
+                    }
+
+                    expect(urlConnections).to(haveCount(3))
+                    expect(NSRegularExpression.match(urlConnections[0].absoluteString, pattern: "//realtime.ably.io")).to(beTrue())
+                    expect(NSRegularExpression.match(urlConnections[1].absoluteString, pattern: "//[a-e].ably-realtime.com")).to(beTrue())
+                    expect(NSRegularExpression.match(urlConnections[2].absoluteString, pattern: "//realtime.ably.io")).to(beTrue())
+                }
+
             }
 
             // RTN18