<img height="1" width="1" style="display:none;" alt="" src="https://px.ads.linkedin.com/collect/?pid=2975524&amp;fmt=gif">
BLOG

Be Prepared: What to Bring when Troubleshooting a Network

October 19, 2015

Picture this - I’m troubleshooting a problem with a client. We get into the elevator go down a few floors, past a few card access protected doors, into the server room and get ready to start troubleshooting. I ask for an AC outlet to connect my laptop and other tools into. Oops, only one outlet available in that rack and no power bars to be found. So now the client scrambles around looking for a power bar or if he can temporarily unplug something. And the story goes on with Ethernet ports, etc, followed up with multiple trips back to the IT storage room and calls to other staff looking for stuff.

In this blog we will go over what you should have with you on your next engagement troubleshooting a network.

The point is that I am onsite for a limited time and cannot afford to spend extra time looking for power bars, patch cables, etc. To make this a bit more stressful is at times I may be working after hours or at site with no equipment.

The other week someone emailed me and asked what tools do I bring along to by engagements and I answered, “It depends on what I’m doing and the technology I’m working with.” The goal is to bring just enough that you are not weighed down like a pack mule, but to bring some extra equipment to avoid some obvious issues. For example a few patch cables of varying lengths. How many times have you cursed your cable because its 1 inch too short, or you run into some equipment that still requires an old fashion cross over cable?

 

What Your Network Is Missing 7 Tools To TAP

I think every analyst should have a written or mental list of what equipment they should always have on hand to reduce the number of things that may trip you up. In this video I cover what I’m bringing along for a VOIP baselining/troubleshooting engagement.


 

 

Want to learn more about the many network tools that help you manage your network? Download What Your Network Is Missing: 7 Tools To TAP

 

See Everything. Secure Everything.

Contact us now to secure and optimized your network operations
Contact Us

Heartbeats Packets Inside the Bypass TAP

If the inline security tool goes off-line, the TAP will bypass the tool and automatically keep the link flowing. The Bypass TAP does this by sending heartbeat packets to the inline security tool. As long as the inline security tool is on-line, the heartbeat packets will be returned to the TAP, and the link traffic will continue to flow through the inline security tool.

If the heartbeat packets are not returned to the TAP (indicating that the inline security tool has gone off-line), the TAP will automatically 'bypass' the inline security tool and keep the link traffic flowing. The TAP also removes the heartbeat packets before sending the network traffic back onto the critical link.

While the TAP is in bypass mode, it continues to send heartbeat packets out to the inline security tool so that once the tool is back on-line, it will begin returning the heartbeat packets back to the TAP indicating that the tool is ready to go back to work. The TAP will then direct the network traffic back through the inline security tool along with the heartbeat packets placing the tool back inline.

Some of you may have noticed a flaw in the logic behind this solution!  You say, “What if the TAP should fail because it is also in-line? Then the link will also fail!” The TAP would now be considered a point of failure. That is a good catch – but in our blog on Bypass vs. Failsafe, I explained that if a TAP were to fail or lose power, it must provide failsafe protection to the link it is attached to. So our network TAP will go into Failsafe mode keeping the link flowing.

Glossary

  1. Single point of failure: a risk to an IT network if one part of the system brings down a larger part of the entire system.

  2. Heartbeat packet: a soft detection technology that monitors the health of inline appliances. Read the heartbeat packet blog here.

  3. Critical link: the connection between two or more network devices or appliances that if the connection fails then the network is disrupted.

NETWORK MANAGEMENT | THE 101 SERIES