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Is it possible to sniff some packets from a friend network from my network?

If it's possible, how?

marked as duplicate by Steffen Ullrich, CaffeineAddiction, S.L. Barth, Anders, Gilles Feb 19 '17 at 12:34

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You can sniff the packets provided that you have access to the path the packets are travelling. Suppose Router1 belongs to your friend and Router2 is your own router. You would (1) need access to Router1's network, or (2) packets would need to travel onto your network for you to be able to sniff these packets.

Network traffic can be forwarded using routing protocols and ACLs that send traffic from Router 1's network (say to Router 2's network (say Traffic can then be mirrored using port spanning or port mirroring for later analysis. This can be filtered by IP address or port to examine specific traffic, such as that from the network.

An alternative is to take advantage of unpatched or zero-day vulnerabilities, and potentially take a more active approach to execute attacks on, or penetrate the network(s) on which the packets are travelling. However, be aware that there are ethical and legal implications to be considered which are beyond the scope of your question.

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