Sniffing in a Routed Environment

All of the techniques for tapping into the wire on a switched network are available on routed networks as well. The only major consideration when dealing with routed environments is the importance of sniffer placement when you are troubleshooting a problem that spans multiple network segments.

As you’ve learned, a device’s broadcast domain extends until it reaches a router, at which point the traffic is handed off to the next upstream router. In situations where data must traverse multiple routers, it is important to analyze the traffic on all sides of the router.

For example, consider the communications problem you might encounter in a network with several network segments connected via a variety of routers. In ...

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