Detecting Network Packet Loss

Terry Slattery
Principal Architect

I’ve been writing blogs for for the past several months. I thought that links from here would be useful so that anyone following my blog posts can find them too.

The blog post that I did in December was about detecting network packet loss. It was based on working with a couple of customers where there was significant application slowness. In one case it was a video conferencing system and in another case it was business applications.

It was easy to determine that there was packet loss in the video case. The video was crummy. The task then turned to determining why. Read the article (see link below) to see what caused it.

In the second case, we were doing a network assessment because there were significant complaints that applications were slow. The design part of the assessment turned up a few things, but nothing really significant. However, the network performance part of the assessment found that some key infrastructure links were dropping significant numbers of packets as well as a lot of edge ports with duplex mismatch. While working on this case, I decided that I need to start looking at raw interface error/drop counts as well as percentages. Read the article to see why.

Both stories are in the article Detecting Network Packet Loss.


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Nick Kelly

Cybersecurity Engineer, Cisco

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” dela Cruz Jr.

CCDP, CCNA V, CCNP, Cisco IPS Express Security for AM/EE
Field Solutions Architect, Tech Data

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 Cavanaugh

CCIE #1066, CCDE #20070002, CCAr
Chief Technology Officer, Practice Lead Security Services, NetCraftsmen

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.