New Nexus 9K Items
When using NetMRI in consulting engagements, we are often asked which of the NetMRI issues are the most important to track. That’s a relatively easy question to answer and really doesn’t depend on whether a NetMRI is in use or not. Regardless of the tools, we want to track the same things. In the lists below, many of the issues are obvious, so I’ll skip an explanation. I will elaborate on the items that I think may not be obvious.
Most networks today support business functions that are critical to the ongoing operation of the business. The first issues to track are environmental, because they are the ones that fail more frequently.
We rarely see networks that don’t have some level of redundancy, so it is important to look for failures within the redundant systems. Router redundancy failures and key interface failures are at the top of the list here. (I mentioned these in last week’s blog post New Year Resolution: Run a Clean Network and include them here for completeness.)
The Router Interface and Switch Trunk Port down issues mentioned above are particularly important because they are much easier to overlook. Most organizations don’t take the time to shutdown an unused interface or to remove an old description, making it difficult to tell whether a down interface is due to a link failure. It is easy to miss a key interface failure. An outage occurs later (often much later) when the redundant interface goes down. The best way to manage the network is to shutdown each unused router interface and switch trunk port if it is not used. Then any interfaces or trunk ports that are found in up/down state are due to a failure and should be corrected.
Then we start looking at performance related issues. Performance is typically where most people start looking at networks, because the tools have existed for a long time to look at network performance. What’s often not obvious is how to identify high utilization during business hours.
Once the above issues are being addressed, configuration consistency is next on the list. To check configuration consistency, the network management system will need tools to allow you to identify configurations that don’t match your configuration templates. This is more than checking that a config has certain statements. It needs to be able to handle statements that must appear in a certain order (think ACLs here). It must also be able to identify configurations that contain some statements but not other statements (e.g., make sure the ACL hasn’t been extended or make sure that an undesirable routing protocol is not configured).
With the above checks and alerts, you are well on your way to handling the majority of common network problems, making your network much more stable. In a redundant network, you’ll have the ability to correct most network problems before they cause an outage, and that’s what’s important in a smoothly operating network.
NetCraftsmen would like to acknowledge Infoblox for their permission to re-post this article which originally appeared in the Applied Infrastructure blog under http://www.infoblox.com/en/communities/blogs.html
Nick has over 20 years of experience in Security Operations and Security Sales. He is an avid student of cybersecurity and regularly engages with the Infosec community at events like BSides, RVASec, Derbycon and more. The son of an FBI forensics director, Nick holds a B.S. in Criminal Justice and is one of Cisco’s Fire Jumper Elite members. When he’s not working, he writes cyberpunk and punches aliens on his Playstation.
Virgilio “Bong” has sixteen years of professional experience in IT industry from academe, technical and customer support, pre-sales, post sales, project management, training and enablement. He has worked in Cisco Technical Assistance Center (TAC) as a member of the WAN and LAN Switching team. Bong now works for Tech Data as the Field Solutions Architect with a focus on Cisco Security and holds a few Cisco certifications including Fire Jumper Elite.
John is our CTO and the practice lead for a talented team of consultants focused on designing and delivering scalable and secure infrastructure solutions to customers across multiple industry verticals and technologies. Previously he has held several positions including Executive Director/Chief Architect for Global Network Services at JPMorgan Chase. In that capacity, he led a team managing network architecture and services. Prior to his role at JPMorgan Chase, John was a Distinguished Engineer at Cisco working across a number of verticals including Higher Education, Finance, Retail, Government, and Health Care.
He is an expert in working with groups to identify business needs, and align technology strategies to enable business strategies, building in agility and scalability to allow for future changes. John is experienced in the architecture and design of highly available, secure, network infrastructure and data centers, and has worked on projects worldwide. He has worked in both the business and regulatory environments for the design and deployment of complex IT infrastructures.