IP address log

I don't know about a log file.

Does the router support DHCP reservations?

This is a process where you grab the PCs MAC address (hardware address), from ipconfig /all, and assign a permanent IP address to that MAC address. With DHCP enabled the PC will always get the same IP address, unless they manually hard code an address and turn of DHCP on the PC.

In the past I set up a scheduled task which reset the TCP/IP parameters because my kids were bypassing OPENDNS for web filtering and using Googles DNS servers, which has no filtering. Using the same process, one could also force DCHP on, so if they did set up a static IP address is would be periodically reset.

Such as task can be hidden, but if the person is desparate to bypass any controls you put in place, you will be playing cat and mouse until you try disciplinary consequences.

TanyaC said:

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Such as task can be hidden, but if the person is desparate to bypass any controls you put in place, you will be playing cat and mouse until you try disciplinary consequences.

You are absolutely right! The disciplinary measures will be the last resort I will consider.

I know DHCP reservation, but I can't tell you whether my router (FRITZ!Box 7390) handles that. Will check ... but, if the MAC address (laptop) is assigned to a fix address, then he still gets in using DHCP (that's what he did). Remedy would be to lock him on the router side to a fix IP address! However if he logs in using a DHCP address, I grab him on the DHCP, lock it to the MAC and use parental control on that one, he's blocked probably. Is all this correct? I'll give it a try ...

Related question ...

Is any software able to change the TCP/IP IP4 settings from fix IPs to automatic (DHCP) by its own?

Thanks,

I think you're on the right track. DHCP reservations LOCK a MAC address to a FIXED address with DHCP enabled.

Regarding other software whilst I have never used any such, as TCP/IP configuration in windows is relataively simple and windows has plenty of tools to manage it, I would think there would absolutely have to be software out there that can play with settings. I have seen stuff for tuning TCP/IP but not specifically for switching between static/DHCP, because as I said, it's a simple enough task to do it in Windows.

TCP/IP configuratrion in windows is a combination of registry settings and a number of files in the system32\drivers\etc folder. The group policy editor (gpedit.msc snapin), and NETSH Command line tool can be used to manager these settings.

If the PC is running Windows 7 pro, enterprise or ultimate, you can manage settings via a group policy, so that everytime the person logs on the policy is applied. You can also use the NETSH settings via a hidden scheduled task if the person continues to "hack"..

Good luck. Drop us a line if you need more help.

I had a look at the router manual and it looks like it doesn't support DHCP reservations with MAC addresses, or MAC address filtering. I believe that without that feature you will find it difficult to lock a computer to a specific IP address. Entering a static address won't work, becuase they will probably just change it.

That leaves you with using a group policy (if your version of windows supports it), or hidden scheduled tasks to reset the configutation periodically, so if they do change it it won't last long. Or talking with them and setting down the rules.

If you were only after content filtering you could set up the DNS servers to OpenDNS and create yourself an account there. But again, they can simply change the DNS settings and bypass that too.

I had the same issue a couple fo years ago.. Here's a couple of related posts..

http://forums.whirlpool.net.au/archive/1345860
Stop IP address changes on PCs

You could write a batch file that gets the ipconfig and saves it to the disk. Then setup a task schedule to run ever 5 minutes then just check the log to see if it changes.

I can write one up for you if you want.

Update just made it since i was bored.

Create a new text file then past the coded text below in and save it. Then rename it from .txt to .bat

There are a few things that can change depending on how many adapters you have.

I can modify it specify for you if you post your Ipconfig /all output.

I chose the filters the way i did because my network has multiple adapters not knowing how many will show up on the OP's i didnt want him to get lost in addresses.

Code:

echo off
ipconfig.exe /all > C:\ipconfig_output.txt
date /T >> c:\ipconfig.log 
time /T >> c:\ipconfig.log
findstr /c:"Local Area Connection:" c:\ipconfig_output.txt >> c:\ipconfig.log

findstr /c:"192.168.1" c:\ipconfig_output.txt >> c:\ipconfig.log

del c:\ipconfig_output.txt

You can also add a task that deletes the c:\ipconfig.log file so the file doesnt get to big.

Task Schedule settings.

in picture let me know if you have any issue. the file that you will need to look at for the address is c:\ipconfig.log

geohei said:

Nevertheless, I'd like to know if Windows 7 features a log of IP addresses used for a certain interface (WLAN in my case). Google as well as the search function of this forum didn't reveal any hints.

I do not believe that windows keeps track of IP adresses used on an interface, or for an entire machine.

Again, you could set up a scheduled task to write the IP address to a file periodically.

Tanya