From b74b71ecb31ebb4147f52e04faebfd01895fe451 Mon Sep 17 00:00:00 2001
From: Madhu Venugopal <madhu@docker.com>
Date: Thu, 7 Jul 2016 16:10:43 -0700
Subject: [PATCH] fixes #23983

Signed-off-by: Madhu Venugopal <madhu@docker.com>
(cherry picked from commit 6a4b21bd863f955d05e5df1e54be4dfcf6889870)
Signed-off-by: Tibor Vass <tibor@docker.com>
---
 api/server/router/network/network_routes.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/api/server/router/network/network_routes.go b/api/server/router/network/network_routes.go
index 7e5b94cb91..ebf2ce2872 100644
--- a/api/server/router/network/network_routes.go
+++ b/api/server/router/network/network_routes.go
@@ -81,6 +81,10 @@ func (n *networkRouter) postNetworkCreate(ctx context.Context, w http.ResponseWr
 		return err
 	}
 
+	if _, err := n.clusterProvider.GetNetwork(create.Name); err == nil {
+		return libnetwork.NetworkNameError(create.Name)
+	}
+
 	nw, err := n.backend.CreateNetwork(create)
 	if err != nil {
 		if _, ok := err.(libnetwork.ManagerRedirectError); !ok {