recieve-only – About Things | A Hans Scharler Blog https://nothans.com Life, Comedy, Games, Tech, Marketing, and Community Thu, 11 Aug 2022 21:54:09 +0000 en-US hourly 1 https://i0.wp.com/nothans.com/wp-content/uploads/2023/02/cropped-settings.png?fit=32%2C32&ssl=1 recieve-only – About Things | A Hans Scharler Blog https://nothans.com 32 32 114568856 Passive Packet Capturing https://nothans.com/passive-packet-capturing https://nothans.com/passive-packet-capturing#respond Tue, 29 May 2007 18:11:00 +0000 http://nothans.com/passive-packet-capturing User A to User B packet data traffic can be monitored through a HUB by User C using a “receive‑only” Ethernet cable.

Receive Only Cable Diagram

On the HUB end of the cable, there is a loop between TX and RX to activate the HUB port. Any traffic through the HUB will now include this port in the broadcasts.

User C taps onto the loop by its receive pins.

Once the connections are made to the HUB, User C will receive all packets that flow through the HUB, but User C will not transmit any packets towards the HUB (no DHCP requests and no ARP requests).

The NIC on User C is in promiscuous mode capturing all incoming packets only.

Using a receive-only Ethernet cable in this configuration allows for the ability to passively capture packets, while not actively being a part of the network.

Network administrators can actively test for devices in promiscuous mode, monitor for DHCP and ARP requests, and review MAC tables to determine the presence of a packet analysis tool.

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