The default gateway IP address is the address of the next hop router the switch uses to reach a non-local IP host when the switch does not know the return route. During a normal management protocol exchange with an IP client host, the switch simply sends its response onto the same route from which the request was received. The default gateway route is only used when the switch itself initiates an exchange, e.g., a TFTP upgrade, with the client. The default gateway IP address is global to all VLANs, which is unlike the unique per-VLAN management IP address and subnet mask. A write to this object will take effect immediately, replacing the previous address, if any. The default is 0.0.0.0, or no address.