diff --git a/tools/test/topos/sys-nonlinear-4.config b/tools/test/topos/sys-nonlinear-4.config
new file mode 100644
index 0000000..b843146
--- /dev/null
+++ b/tools/test/topos/sys-nonlinear-4.config
@@ -0,0 +1,79 @@
+[{linc,
+     [{of_config,disabled},
+      {software_desc,<<"LINC-OE OpenFlow Software Switch 1.1">>},
+      {capable_switch_ports,
+          [{port,1,[{interface,"dummy"},{type,optical}]},
+           {port,2,[{interface,"dummy"},{type,optical}]},
+           {port,5,[{interface,"dummy"},{type,optical}]},
+           {port,6,[{interface,"dummy"},{type,optical}]},
+           {port,7,[{interface,"dummy"},{type,optical}]},
+           {port,8,[{interface,"dummy"},{type,optical}]},
+           {port,9,[{interface,"dummy"},{type,optical}]},
+           {port,10,[{interface,"dummy"},{type,optical}]},
+           {port,3,[{interface,"tap3"}]},
+           {port,4,[{interface,"tap4"}]}]},
+      {capable_switch_queues,[]},
+      {optical_links,[{{1,20},{3,30}},{{3,31},{2,21}},{{1,22},{4,30}},{{4,31},{2,22}}]},
+      {logical_switches,
+          [{switch,1,
+               [{backend,linc_us4_oe},
+                {datapath_id,"00:00:ff:ff:ff:ff:ff:01"},
+                {controllers,[{"Switch0-Controller","10.1.8.147",6633,tcp}]},
+                {controllers_listener,disabled},
+                {queues_status,disabled},
+                {ports,
+                    [{port,1,[{queues,[]},{port_no,20}]},
+                     {port,7,[{queues,[]},{port_no,22}]},
+                     {port,3,[{queues,[]},{port_no,10}]}]}]},
+           {switch,3,
+               [{backend,linc_us4_oe},
+                {datapath_id,"00:00:ff:ff:ff:ff:ff:03"},
+                {controllers,[{"Switch0-Controller","10.1.8.147",6633,tcp}]},
+                {controllers_listener,disabled},
+                {queues_status,disabled},
+                {ports,
+                    [{port,5,[{queues,[]},{port_no,30}]},
+                     {port,6,[{queues,[]},{port_no,31}]}]}]},
+           {switch,2,
+               [{backend,linc_us4_oe},
+                {datapath_id,"00:00:ff:ff:ff:ff:ff:02"},
+                {controllers,[{"Switch0-Controller","10.1.8.147",6633,tcp}]},
+                {controllers_listener,disabled},
+                {queues_status,disabled},
+                {ports,
+                  [{port,2,[{queues,[]},{port_no,21}]},
+                  {port,8,[{queues,[]},{port_no,22}]},
+                  {port,4,[{queues,[]},{port_no,11}]}]}]},
+           {switch,4,
+              [{backend,linc_us4_oe},
+               {datapath_id,"00:00:ff:ff:ff:ff:ff:04"},
+               {controllers,[{"Switch0-Controller","10.1.8.147",6633,tcp}]},
+               {controllers_listener,disabled},
+               {queues_status,disabled},
+               {ports,
+                 [{port,9,[{queues,[]},{port_no,30}]},
+                 {port,10,[{queues,[]},{port_no,31}]}]}]}]}]},
+ {epcap,[{verbose,false},{stats_interval,10}]},
+ {enetconf,
+     [{capabilities,
+          [{base,{1,0}},
+           {base,{1,1}},
+           {startup,{1,0}},
+           {'writable-running',{1,0}}]},
+      {callback_module,linc_ofconfig},
+      {sshd_ip,any},
+      {sshd_port,1830},
+      {sshd_user_passwords,[{"linc","linc"}]}]},
+ {lager,
+     [{handlers,
+          [{lager_console_backend,debug},
+           {lager_file_backend,
+               [{"log/error.log",error,10485760,"$D0",5},
+                {"log/console.log",info,10485760,"$D0",5}]}]}]},
+ {sasl,
+     [{sasl_error_logger,{file,"log/sasl-error.log"}},
+      {errlog_type,error},
+      {error_logger_mf_dir,"log/sasl"},
+      {error_logger_mf_maxbytes,10485760},
+      {error_logger_mf_maxfiles,5}]},
+ {sync,[{excluded_modules,[procket]}]}].