Nat Probe v1.0

Little program to test which hosts allow NAT in your Local Area Network (LAN).

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This little, but very usefull program, try to sends ICMP packet out the LAN, and detect all the host that allow it. Whit this you can find bugs in your (company?) network (or others), for example hosts tha allow p2p connections.


When we use a Gateway, we send the packets with IP dest of the target, but the dest mac on the ethernet is the mac at the Gateway. If we send a packet to the diferents macs in the lan, we can know who is the gateway when we recive an response from this mac.

Some times we can discover more than one box configured to be an gateway, generally, this is an wrong configuration, and the box will response with an ICMP-Redirect. This is the same, becouse the script only verify if the mac response.

python -m 00:00:0d:ff:11 -d 2xx.x4.1x.xx

We can send an packet to a singular mac,

python -f /tmp/ethers.log -d 2xx.x4.1x.xx

/tmp/ethers must be a list of macs separated by a newline.

More information: here.

Post scriptum

Compliance Mandates

  • Network Monitoring :

    PCI DSS Requirements 3, 4, SOX DS13.4, HIPAA 164.310(d)(1),
    164.312(a)(2)(iv), FISMA SI-4, AU-2, ISO 27001/27002 12.5.4, 15.1.5


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