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

Security Connectivity Report: Optimizing Network Design for Forensic Analysis

July 23, 2015

Malicious attacks can take an average of 256 days to identify while data breaches caused by human error take an average of 158 days to identify.

- Ponemon Institute’s Cost of Data Breach Study: Global Analysis

It goes without saying – the longer a security breach goes undetected, the greater the damage. As companies worldwide build out their incident response plans, many are investing heavily in forensic analysis solutions to better understand what systems were compromised in the event a breach occurs. Solutions like the FireEye Network PX Series Forensic Platform let security professionals quickly reconstruct the details of the attack and see what systems and records were compromised in the process.

As we all know from watching detective shows, forensic teams need to look at every shred of evidence to be effective. The same goes true for their InfoSec counterparts. If an IT forensic analysis tool doesn’t get all the network data – and years of it – it cannot possibly piece together what happened.

When beginning a computer forensic analysis and data capture project, security specialists must ensure that the appliance they use will be able to see every bit, byte and packet® of the traffic that flows in and out of the network. Therefore, a proper network design and connectivity plan is critical to ensure the success of the project.

Examine the Source

When it comes to collecting network data, most people believe that all sources of information are created equal. That idea just isn’t true in today’s busy networks. When traffic is routed from a live network element – even a switch – there is a good chance that the element itself will corrupt the transmission. They can change frame timing, introduce delays and/or drop packets, especially during unexpected traffic spikes. While it might not be a big deal in the grand scheme of network management, it can be a real problem if the lost or corrupted traffic held the key to deciphering the source of a breach.

Instead of getting traffic information indirectly from a network element – connect forensic appliances to the network itself. For example, a network TAP in bypass mode is a purpose built hardware devices that when inserted into the network will copy all the information that passes by it and send it to a separate appliance for analysis – all without altering it. While they are used to support firewalls and other in-line security devices, they are also ideal for ensuring that all out-of-band appliances receive 100% of the information that flows through it.

Choose your Network Entry Points

To quickly diagnose security issues, you need to collect data across your entire environment. When forensic analyzers are connected to the network at multiple points (in front of and behind the firewall; on either side of web servers; inside the datacenter), infosec professionals can compare the data to see where and how traffic changes from system to system. Armed with more information, forensic analyzers can spot and analyze suspicious activity – and hopeful shut down attacks before a theft can occur.  

Match the Network’s Physical Environment

When connecting forensic appliances, it is important to fit the network TAP to your environment’s exact specifications. Find out what type of cabling your network uses (copper or fiber) and the speed at which it runs (1G, 10G, 40G, 100G) and then choose the network TAPs that matches your configuration data.

The data capture element of a forensic analysis project works best when coupled with an optimized network design and connectivity plan. If you’re going to go through the effort of deploying a forensic analysis solution, why wouldn’t you do it right? Network TAPs represent a small percentage of the average security deployment project (5-10% max), however, their value to a security strategy is much higher. After all, if a forensic analyzer doesn’t see all the network traffic, it can’t solve the mystery or help companies limit their losses in the event a breach occurs.

If you’re getting ready to deploy a forensic analyzer FireEye and need help with network design, the designers at Garland can show you how to maximize visibility in the process.

IT security garland Technology tool deployment

See Everything. Secure Everything.

Contact us now to secure and optimized your network operations

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