network connecting device 303 vlan 502 is composed of a network device 315 connected to a fourth port 355 and a network device 317 connected to a fifth port 357 wherein both of the fourth port 355 and the fifth port 357 are located on the network connecting device 301 a network device 331 connected to an eighth port 385 and a network device 333 connected to a tenth port 387 wherein both of the eighth port 385 and the tenth port 387 are located on the network connecting device 303 vlan 504 is composed of a network device 319 connected to an eighth port 363 and a network device 321 connected to a ninth port 365 wherein both of the eighth port 363 and the ninth port 365 are located on the network connecting device 301 a network device 335 connected to a second port 403 and a network device 337 connected to a fourth port 405 wherein both of the second port 403 and the fourth port 405 are located on the network connecting device 305 vlan 506 is composed of a network device 323 connected to an eleventh port 367 and a network device 325 connected to a twelfth port 369 wherein both of the eleventh port 367 and the twelfth port 369.