Five network troubleshooting tips for a snow day

Snow days may slow most of the UK down, but when users are away, IT has time for network diagnostics and troubleshooting. Learn about network auditing, network mapping and IP address management.

At some point every winter, snow brings the entire United Kingdom to a standstill. In London, that only takes about an inch of snow. The good news for network managers is that an empty office with no complaining users is the perfect time to take on network diagnostics and troubleshooting. The trick is to have a plan for when you find yourself on deserted ground with no sign of the enemy.

Network troubleshooting tip 1: Checking cables

Checking connectivity is a good thing to do when users are away, said Dirk Paessler, CEO of Paessler, a network monitoring firm. This is the time to create a network map, use a monitoring tool and set up alerts that show when something is unplugged or a cable is in trouble. This is also a good time to replace damaged cables.

“Over half the network downtime is caused by cabling faults. Taking the time to map your network and regularly checking the health of cables will prevent avoidable downtime,” Paessler said.

Network troubleshooting tip 2: Auditing and mapping

This is also an opportunity to run a network audit that can discover the entire IT infrastructure. A network audit can ensure that all assets are accounted for and used appropriately in the correct areas of business.

A full network diagnostic can be conducted through an indiscriminate ping search. This will find everything connected to the network, including those long-lost items hiding at the back of the wiring closet.

With users gone, there won’t be a problem if diagnostic exercises bring up a PC or a network switch that needs to be reconfigured.

“This lets you discover devices in the IT estate and to redeploy them for more efficiency,” said Steve Demianyk, channel development manager at Ipswitch’s Network Management Division.

However, doing network maintenance work on the VPN isn’t a good idea since some at-home employees may actually be working remotely.

Network troubleshooting tip 3: Eliminating redundancies

This is a good time to remove useless, redundant applications or ghost machines that slow the network.

The place to begin is with routing, said Dirk Marichal, vice president at Infoblox. The idea is to find where the routing HSRP settings cannot locate peers. When this happens there’s a false sense of security in thinking there are backup links that are actually useless. This problem can be rectified by searching all configurations and correcting the settings that have drifted over time. While this can be done with people in the office, it’s a lot easier to accomplish without an overload of support calls.

“Instead of us digging through hundreds of devices and millions of lines of code, we use the automatic issue list within the Infoblox NetMRI solution to help us find the HSRP problems and other issues in a matter of minutes,” Marichal said. “NetMRI pulls the needles from the haystack so we spend less time aimlessly searching and focus our resources on fixing the issues.”

Network troubleshooting tip 4: Optimizing port use

An empty office is a great time to drill down through all switch ports and identify which are active and which are not. Reclaiming unused switch ports puts an end to wasting money on new switch capacity when much of the existing resources are underused.

Infoblox’s tools, for example, can be used to track switch ports in comparison to end users to measure usage. With this information, you can decide whether to reclaim the port or not.  “Without the information, it's guesswork,” said Marichal. “We tend to err on the side of caution to eliminate risk, but then we waste resources. Now we make the right decisions with all of the information.”  The same effect could be achieved using INS’s Sapphire tool (now owned by BT Global Services).

Network troubleshooting tip 5: IP address management

An empty office can also provide the time to clean up IP address management (IPAM) and find conflicting IP addresses. Drilling down through the entire IP address library offers the ability to clean up the out-of-date information, partial databases and conflicting IP addresses most network administrators are guilty of.

This is also a good time to rethink the overall IPAM strategy, using tools from vendors such as Afilias, Blue Cat Networks and Men&Mice.

Normally networking pros are too busy fire fighting to do this. “IP address resources are a complex component of the network infrastructure and as the day-to-day management can be lax, problems and complexity will arise over time,” Marichal said. Better management will reduce the risk of unknown problems. 

-- Nick Booth is an independent industry analyst. He started working in IT, networking and telecoms in the days when even the visionaries couldn’t see the Year 2000 coming.

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