If you use NetworkManager for network setup, you can easily switch, stop, or start your network connection at any time from within your desktop environment using an applet. NetworkManager also makes it possible to change and configure wireless card connections without requiring root privileges. For this reason, NetworkManager is the ideal solution for a mobile workstation.
Traditional configuration with ifup also provides some ways to switch, stop, or start the connection with or without user intervention, like user-managed devices, but it always requires root privileges to change or configure a network device. This is often a problem for mobile computing, where is not possible to preconfigure all connection possibilities.
Both traditional configuration and NetworkManager can handle network connections with a wireless network (with WEP, WPA-PSK, and WPA-Enterprise access), dial-up, and wired networks both using DHCP and static configuration. They also support connection through VPN.
NetworkManager tries to keep your computer connected at all times using the best connection available. If available, it uses the fastest wired connection. If the network cable is accidentally disconnected, it tries to reconnect. It can find a network with the best signal strength from the list of your wireless connections and automatically use it to connect. To get the same functionality with ifup, a great deal of configuration effort is required.
NetworkManager is currently not able to run multiple network interfaces at the same time. If you need that functionality, you should use the traditional ifup method for setting network connections. It is also generally not intended for use on servers.
NetworkManager is not a suitable solution in the following cases:
You want to use more than one provider for dial-up for one interface.
You want to use more than one active network connection simultaneously.
Your computer is a router for your network.
Your computer provides network services for other computers in your network, for example, it is a DHCP or DNS server.
NOTE: NetworkManager and SCPM
Do not use NetworkManager together with System Configuration Profile Management (SCPM) when SCPM profiles also change network settings. If you want to use SCPM and NetworkManager at the same time, disable the network resource in SCPM configuration.
Traditional configuration is a suitable solution when you need entire control over your connection and in the following cases:
You want to use more than one provider for dial-up for one interface.
Your computer is a router for your network.
Your computer provides network services for other computers in your network, for example, it is a DHCP or DNS server.
You want to use SCPM to control network configuration.