LoveMyTool - Open Community for Network Management and Monitoring

Troubleshooting HTTP Connection Issues With Wireshark (by Tony Fortunato)

I really get excited when I am able to reproduce problems in the lab.

With this specific case, the customer was experiencing errors within their web browsers that looked like either a network or server issue. The specific symptom was that certain images would not display. If you waited a while, and ‘refreshed’ the page, more of it loaded or the entire page loaded properly.

I’m sure you can imagine the chaos this type of intermittent problem causes.  The sequence of events unfolds in the following manner; the client reports the webpage issue to the help desk and the help desk tests the webpage with mixed results.  In either event, the problem goes to the server group who tests and finds nothing wrong, and then the problem goes to the network group which, in most cases, does not see the problem. Then the political fist fights, finger pointing and witch hunt commence…..

Fluke Networks OneTouch At HTTP Testing (by Tony Fortunato)

One thing that consumes a lot of time is comparing performance test results.

This basic task is used during support, implementation and for proof of concepts in design.  The trickiest test is to run 2 tests; one on WiFi and another on the wired side within the same time frame. Many customers are looking for this kind of test to document and compare performance results.

Troubleshooting FTP Errors With Wireshark (by Tony Fortunato)

The most daunting problem to troubleshoot is when the application spits out a generic error that could mean anything.  Here’s the analogy; how helpful is the ‘Check Engine’ light on your car dashboard.

The worst part is when the customer tries to take the cryptic, generic application error message and tries to make sense of it in an attempt to assist the analyst.  Don’t get me wrong, any information is helpful while troubleshooting, but you have to be selective in what you pursue.

In this example FTP works one moment and fails the next.  Of course the customer immediately called the help desk, who pings the ftp server and comments that is up and no outages have been recorded by the network management system.  Then the ticket goes to the server dept who ftp’s without  an issue, unfortunately by now so can the customer.  The server department says the connection error must be a ‘network thing’.

Real Visualization for Network Professionals (by The Oldcommguy)

TAP or SPAN (RSPAN)

By: Tim O’Neill – The Oldcommguy™

Author’s comments:

• All Rights are reserved – Copyright 2013 by The Oldcommguy™!
• No one may repost this article without receiving permission!
• If permission is given then it must be posted as it is, in full context, WITHOUT any changes!

This is an updated version of my original article that was written in 2007 –

http://www.lovemytool.com/blog/2007/08/span-ports-or-t.html

A Super Video Class from Sharkfest by a world class Trainer and Analyst – Betty DuBois –

http://blip.tv/lovemytool/span-port-vs-tap-by-betty-dubois-2290452

and part of the Ixia Team Blog –

http://blogs.ixiacom.com/ixia-blog/to-span-or-to-tap-that-is-the-question/ 

 The goal of Network, Security, Compliance, and Application managers requires FULL visualization of the Network and the packets therein!

Real Visualization is EVERYTHING!

If you cannot see an issue, like an attack, misusage, inefficiency, etc., then how are you going to understand it and resolve it? Here are the REAL facts about needing REAL TAPs!

Moving beyond "It's not the network" (by Chris Greer)

Ok, we get it. It's not the network.

Over the past few years, network engineers have slowly been winning the battle of blame. Even though most people still say "The network is slow" when there is a performance problem, many engineers now have the tools to prove otherwise. Whether they use SNMP to check their infrastructure devices, flow tools to watch for utilization spikes, packet analysis engines to watch-dog applications, or automated performance analyzers with built in alarms, most environments have some type of monitoring in place to help the engineer prove his case.

However, the problem now becomes - what next?