Determine Private IP Address Space

Forgive me if this is a stupid question...I'm a Windows user dipping my toes into Penetration Testing (leading from needing to become PCI compliant) and found it really interesting so far, however I'm still new to Linux.

Basically I want to show that we need network port filtering as at the moment I believe anyone could use one of our publically accessible Ethernet ports to gain access to our LAN. How can I do this stealthy though? Its my understanding that if I use ifconfig eth0 it will tell me the IP address assigned to the network card and the network mask. However isn't it the case that these would've been assigned by DHCP, and therefore its a trivial task to look at the DHCP logs, or filter the address leases to monitor for suspicious activity? Is there a way to determine the private network IP space without using DHCP?

I have tried googling the answer but haven't had any luck yet....I obviously need to improve my google foo!

"Its my understanding that if I use ifconfig eth0 it will tell me the IP address assigned to the network card and the network mask. However isn't it the case that these would've been assigned by DHCP, and therefore its a trivial task to look at the DHCP logs, or filter the address leases to monitor for suspicious activity? Is there a way to determine the private network IP space without using DHCP?"


,.the

Code:

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ifconfig

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command brings up the list of active network interfaces and your l00pback,
you are correct that DHCP automatically gives you an ip address, but you Can also set ur ip add manually.

use 2 commands, take down the network interface, then bring it back up with the desired iP address

(example using ethernet)

Code:

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ifconfig eth0 down

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Code:

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ifconfig eth0 up 192.168.x.x

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