What you will learn in this tip: A good set of network documentation can be extremely valuable in the event of an extreme disaster. People think of servers, storage, etc., and often forget about the plumbing -- i.e., the data/storage networks in their disaster recovery plans.
This tip lists what you should document and make part of your network disaster recovery plan.
Appliance configuration settings
What types of things should you document as part of your network disaster recovery plan? For starters, you should document the configuration settings for every piece of networking hardware in your data center. For example, you should make sure to document (and back up if possible) the configuration settings used by your network routers. Likewise, you should document which ports are open on your firewalls, as well as any rules that might be configured on the device.
Some appliances will actually allow you to export the configuration to an XML file or to some other file format, but other appliances have no such mechanism. Even if you are able to export the device settings it's a good idea to have a written copy of those settings. If a disaster wiped out your data center, then you might not be able to get your hands on the exact make and model of the appliance you were using. If that were to happen, then you wouldn’t be able to import the configuration file and your only option would be to manually configure the new appliance by using the information that you had written down.
Include firmware versions in your network disaster recovery plan
You should make sure you document the firmware version that's in use on each of your hardware appliances. Otherwise, if you're forced to replace an appliance, the new appliance might be running an older or a newer firmware version. If that happens, you might discover that some of the configuration options you're using right now don't exist on the new appliance.
You could also discover that one or more of the appliance’s features works differently, depending on what firmware release the appliance is running.
You should make sure you have a network diagram of your data center. For example, imagine that a router in your data center is struck by lightning. If that were to happen, your configuration documentation will help you to configure the replacement unit, but unless your replacement router is identical to the old one, you may have a tough time figuring out which network cables should be plugged into each port.
This is where a good network diagram comes into play. Sure, you can figure out the appropriate cable arrangement without having a network diagram, but you will be able to get back online more quickly if you have a well-annotated diagram you can use.
Tools like LANsurveyor from SolarWinds can help you produce a network diagram. There are a many different network mapping applications available, and many of them are free.
Another useful thing to keep in your network documentation is the contact information for anyone that might be able to provide you with assistance in the event of an emergency. Your contact information should include:
- Employees in the IT department
- Any vendors that you regularly use
- The technical support contact numbers (and your account number for the tech support lines) for the hardware and software manufacturers.
Finally, you need to have some detailed information about each piece of hardware in your data center. Depending on the scale of the disaster, you could end up having to call technical support, a warranty department or even an insurance company. In any case, they will likely require serial numbers and model numbers for all of your hardware.
If you have to call a software publisher for support, you may need to have your license information handy, as well as the vital statistics for the hardware and the operating system that the software is running on. Remember, your goal is to get things back to normal as quickly as possible, and having all of this information in one place will go a long way toward helping you to accomplish that goal. You don’t want to have to waste time trying to find a serial number sticker on the back of a server, or a license key that you have stashed in a drawer somewhere.
Recovering from a disaster is never easy, but it's a lot easier if you have detailed information about the systems that were affected. Of course compiling the information for your network disaster recovery plan is one thing. Keeping it up to date is quite another challenge.
About the author: Brien M. Posey, MCSE, has previously received Microsoft's MVP award for Exchange Server, Windows Server and Internet Information Server (IIS). Brien has served as CIO for a nationwide chain of hospitals and was once responsible for the Department of Information Management at Fort Knox. You can visit Brien's personal website at www.brienposey.com.
This was first published in March 2011