Enterprise Unix Roundup: Eyeing the Horizon Page 2

Tips of the Trade

Roaming Linux users face interesting challenges as they move from one network to another. Moving from wired to wireless, moving into a different wireless network, and changing from trusted to an untrusted network requires a fair bit of fiddling. Various Linux distributions have their own networking auto-configurators, such as Red Hat's profiles, and Debian's Whereami. If you have tried these, you know that they're better than nothing, but still don't quite do the job.

The NetworkManager utility aims to eliminate fiddling, and "just work." NetworkManager tries to handle roaming all by itself, without user intervention. It runs on all Linux distributions, and in all desktop environments and window managers.

NetworkManager isn't telepathic, but it does try to be sensible. When the user enters a location she has visited before, NetworkManager tries to connect to the last network used there. On laptops with both wired and wireless adapters, NetworkManager tries the wired interface first. Plugging into a wired network switches the connection away from the wireless interface.

Users set up lists of Trusted Networks and Preferred Networks. For example, a wireless connection associated with work would go on the Trusted Networks lists, and WEP/WPA keys automatically loaded. Preferred Networks include public WiFi hotspots, Internet cafes, guest access at another company, and such. Once the user has connected to one of these, NetworkManager will remember, and automatically connect on the next visit.

Any connection must be explicitly added to either list. NetworkManager connects only to networks that it is told to; it does not try to attach to any available network.

NetworkManager works only with DHCP- static IPs are not supported. It is not intended for servers, just desktop and laptop PCs. Get downloads and information at NetworkManager.

Carla Schroder writes the Tips of the Trade section of Enterprise Unix Roundup. She also appears on Enterprise Networking Planet and Linux Planet, covering Linux from the desktop to the server room. She is the author of the Linux Cookbook and the upcoming "Linux Networking Cookbook."

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