A network system (10, 50) to provide connectivity to a computer system, the network system (10, 50) configured as a network logical domain and comprising: a plurality of enclosure groups, whereby each enclosure group is separately communicatively coupled to a network; whereby each of the enclosure groups includes a primary enclosure (14, 52, 154) and one or more sub-enclosures (18, 62,156); whereby each of the primary enclosures (14, 52, 154) comprises a single network switch system (16, 56, 158) that comprises a plurality of physical interface ports, wherein a first one of the plurality of physical interface ports is adapted to communicatively couple to a network; and said network system (10,50) being characterized in that each of the sub-enclosures (18, 62, 156) comprises: a respective computer system to which a network interface card, NIC, is coupled and a downlink extension module, DEM, (20, 66) that is communicatively coupled with the computer system and a respective second one of the plurality of physical interface ports of the network switch system (16, 56, 158) of the respective one of the primary enclosures to provide network connectivity of the computer system to the network via the network switch system (16, 56, 158) in the respective primary enclosure, and in that the network switch system of each of the primary enclosures is coupled to a network switch system of two other primary enclosures. a plurality of enclosure groups, whereby each enclosure group is separately communicatively coupled to a network; whereby each of the enclosure groups includes a primary enclosure (14, 52, 154) and one or more sub-enclosures (18, 62,156); whereby each of the primary enclosures (14, 52, 154) comprises a single network switch system (16, 56, 158) that comprises a plurality of physical interface ports, wherein a first one of the plurality of physical interface ports is adapted to communicatively couple to a network; and said network system (10,50) being characterized in that each of the sub-enclosures (18, 62, 156) comprises: a respective computer system to which a network interface card, NIC, is coupled and a downlink extension module, DEM, (20, 66) that is communicatively coupled with the computer system and a respective second one of the plurality of physical interface ports of the network switch system (16, 56, 158) of the respective one of the primary enclosures to provide network connectivity of the computer system to the network via the network switch system (16, 56, 158) in the respective primary enclosure, and in that the network switch system of each of the primary enclosures is coupled to a network switch system of two other primary enclosures. a respective computer system to which a network interface card, NIC, is coupled and a downlink extension module, DEM, (20, 66) that is communicatively coupled with the computer system and a respective second one of the plurality of physical interface ports of the network switch system (16, 56, 158) of the respective one of the primary enclosures to provide network connectivity of the computer system to the network via the network switch system (16, 56, 158) in the respective primary enclosure, and in that the network switch system of each of the primary enclosures is coupled to a network switch system of two other primary enclosures.