DHCP problem

valmiki.prasad · 01-31-2009, 05:33 PM

Hi all,
I have configured a cisco 2600 router to act as a DHCP server and its working quite fine. Now I need how to restrict the PCs from changing their IP addresses ( one should not manually configure their PC ip address. The router should prevent him from changing the IP ) Is there any extra configuration needed in the router?? Please suggest me.

OR

Is there any setting in the PC that prevents the user from changing their IP (other than group policy settings)

Thanks in advance.

**johnwill** · 02-02-2009, 05:06 PM

You can use DHCP reservations to lock an IP address to a MAC address. If the user as administrative rights, it's going to be pretty tough to keep him from tinkering with the settings.

The usual way to deal with this is by firing a couple of them if they continually violate company policy, that usually gets the message across to the rest of them.

You could take a look at this utility, it might slow them down.

http://www.dougknox.com/xp/utils/xp_securityconsole.htm

valmiki.prasad · 02-06-2009, 05:48 AM

Thanks for reply,
But dhcp reservation is a permanent ip address allotment to that particular MAC address.
I need to know that what happens if that user changes his ip address?? whether the router permits or not??. What happens if his ethernet card fails??

**johnwill** · 02-08-2009, 10:28 AM

If the user manually overrides the IP address, and you allow him administrative access to do so, you're out of luck.

If his Ethernet card fails, you have to configure the new MAC/IP mapping. If you have enough cards failing for this to be an issue, I'd be looking for the reason.

**johnwill** · 02-08-2009, 10:28 AM

If the user manually overrides the IP address, and you allow him administrative access to do so, you're out of luck.

If his Ethernet card fails, you have to configure the new MAC/IP mapping. If you have enough cards failing for this to be an issue, I'd be looking for the reason.

01-31-2009, 05:33 PM	#1 (permalink)
valmiki.prasad Registered User Join Date: Feb 2008 Location: India Posts: 61 OS: Windows Vista Home Premium	DHCP problem Hi all, I have configured a cisco 2600 router to act as a DHCP server and its working quite fine. Now I need how to restrict the PCs from changing their IP addresses ( one should not manually configure their PC ip address. The router should prevent him from changing the IP ) Is there any extra configuration needed in the router?? Please suggest me. OR Is there any setting in the PC that prevents the user from changing their IP (other than group policy settings) Thanks in advance.

02-02-2009, 05:06 PM	#2 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 41,748 OS: Windows 7, XP-Pro, Vista, Linux Blog Entries: 1	Re: DHCP problem You can use DHCP reservations to lock an IP address to a MAC address. If the user as administrative rights, it's going to be pretty tough to keep him from tinkering with the settings. The usual way to deal with this is by firing a couple of them if they continually violate company policy, that usually gets the message across to the rest of them. You could take a look at this utility, it might slow them down. http://www.dougknox.com/xp/utils/xp_securityconsole.htm __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience

02-06-2009, 05:48 AM	#3 (permalink)
valmiki.prasad Registered User Join Date: Feb 2008 Location: India Posts: 61 OS: Windows Vista Home Premium	Re: DHCP problem Thanks for reply, But dhcp reservation is a permanent ip address allotment to that particular MAC address. I need to know that what happens if that user changes his ip address?? whether the router permits or not??. What happens if his ethernet card fails??

02-08-2009, 10:28 AM	#4 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 41,748 OS: Windows 7, XP-Pro, Vista, Linux Blog Entries: 1	Re: DHCP problem If the user manually overrides the IP address, and you allow him administrative access to do so, you're out of luck. If his Ethernet card fails, you have to configure the new MAC/IP mapping. If you have enough cards failing for this to be an issue, I'd be looking for the reason. __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience

02-08-2009, 10:28 AM	#5 (permalink)
johnwill Manager, Networking Forums Join Date: Sep 2002 Location: S.E. Pennsylvania, US Posts: 41,748 OS: Windows 7, XP-Pro, Vista, Linux Blog Entries: 1	Re: DHCP problem If the user manually overrides the IP address, and you allow him administrative access to do so, you're out of luck. If his Ethernet card fails, you have to configure the new MAC/IP mapping. If you have enough cards failing for this to be an issue, I'd be looking for the reason. __________________ If TSF has helped you, Tell us about it! or Donate to help keep the site up! Microsoft MVP - Windows Desktop Experience