Re-thinking remote management

KVM using IP is looking more attractive to network managers who are in charge of lots of boxes.

A couple of months ago, I discussed in-band vs. out-of-band network management. One of the points I raised was how in-band management alone was insufficient for maintaining a highly reliable network, since it can be rendered useless by problems on the network. The solution, I suggested, is the use of out-of-band solutions as a failover strategy.

This month, I’d like to look at a similar issue as it affects server management. Network managers have to manage lots of servers. Their networks depend on DNS servers and RADIUS servers and all kinds of other boxes. These boxes are often geographically dispersed all across the organization. Network managers are faced with the challenge of being able to troubleshoot and proactively administer a variety of Wintel and Unix/Linux machines in multiple locations.

Over the years, a variety of strategies have emerged for tackling the challenge of managing remote servers. One common approach is the use of remote control software. Remote control tools let you take over a machine and operate it as though you were right there, typing on its keyboard and clicking with its mouse.

The problem with remote control software is analogous to the problem with in-band network management. The managed machine actually has to be running for the remote control software to work. That’s because this approach depends on a piece of software running on the managed machine. If the machine is flaking out a bit, it can disable the remote control functions.

Also, with this method, you can’t maintain control of the machine during a re-boot—something that’s often essential when re-configuring software or system settings. That’s because the remote control software on the managed machine requires the operating system to be up and running. Obviously, it has to wait for the OS to boot up before it can kick in.

The alternative is KVM switching technology. KVM stands for “keyboard, video and mouse.” The technology plugs into a managed system’s peripheral ports so that your keyboard, mouse and monitor behave as if they were directly attached to it. Thus—unlike remote control software—it doesn’t need any software running on the managed machine. You can power up a machine and watch it booting up right on your monitor. You can even interrupt the boot process to do diagnostics or tweak some settings.

The problem with conventional KVM switches is that they rely on analog technology. The analog signals between a computer and its KVM peripherals are simply switched to a manager’s machine. This creates several difficulties, including: the need for dedicated cabling between the switch and each managed machine, as well as between the switch and each manager’s PC; and fairly short distance restrictions on the length of those cable runs. These difficulties have limited the appeal of KVM technology to organizations that are looking for flexible, anytime, anywhere management of server resources.

Now, however, a variety of KVM solutions using IP are beginning to show up in the marketplace. These solutions convert analog KVM signals to digital signals that can then be sent over IP—eliminating distance limitations and allowing multiple KVM sessions to be carried over a common network connection. With KVM using IP, technicians can quickly take control of server resources, thereby increasing the reliability of critical IT infrastructure. This hands-on control capability can also enable a smaller number of technicians to manage a greater number of more geographically dispersed machines, thereby lowering IT staffing costs.

Of course, such IP-based access also raises some significant security issues. From what I’ve seen, KVM using IP doesn’t come cheap, but as network managers continue to be forced to find ways to manage more equipment without hiring more staff, KVM using IP is likely to grow in its appeal and its value.

Liebmann is an independent consultant specializing in the application of networking technologies to strategic business challenges. Send comments for publication to liebmann@comnews.com.