Solved Scope not using correct default gateway in superscope

September 12, 2013 at 06:23:16
Specs: Server 2003
Hello,

My problem is i have run out of ip addresses on my dhcp. To solve this i have created a superscope and added another child scope to it. All the settings remained the same and clients are getting the new ip addresses from the new scope but, the default gateway is not correct.

The old scope is 10.192.30.21 - 10.192.30.126,subnet 255.255.255.128, default gateway 10.192.30.1

The new scope is 10.192.31.21 - 10.192.31.126, subet 255.255.255.128 but the default gateway that is shown on the clients is 10.192.31.1.


How can i fix this? As i said all the settings in setting up the scope are the same.


Regards


See More: Scope not using correct default gateway in superscope

Report •

#1
September 12, 2013 at 07:23:09
Have you specifically set the default gateway to supply to clients in the properties of the scope?

Report •

#2
September 12, 2013 at 07:27:50
The default gateway is now showing correctly 10.192.30.1 because i forgot the exclusions. But still cant ping the server or get internet. Did i miss a step in TCP/IP or anything?

*EDIT*
I can't ping any other clients on the network, the clients are getting the new ip addresses but no internet access.

message edited by RaviR


Report •

#3
September 12, 2013 at 12:27:00
✔ Best Answer
"Did i miss a step in TCP/IP ?"

Yeperdo! I think you missed a couple of ip subnetting lessons.

To start you should not be creating superscopes when you are not even using the entire subnet. If you were using 255.255.255.0 you would have 254 host ip addresses instead of only 126. No superscope required.

10.192.30.21 - 10.192.30.126,subnet 255.255.255.128
gives you a range of 10.192.30.0 - 10.192.30.127 and only provides 126 host addresses.

Now if you wanted to go up a notch and superscope you would use the same start of 10.192.30.x and use 255.255.254.0 which would give you a range of 10.192.30.0 - 10.192.31.255 which would provide 510 host ip addesses.

The new scope you made is not a superscope and in fact is a completely different subnet than the first one and that is why Windows correctly set the gateway to .1 as default which is why it doesn't work.

You would also want to note that 10.192.30.1 is not in the range of the 10.192.31.x subnet so its an invalid gateway for that subnet.

Answers are only as good as the information you provide.
How to properly post a question:
Sorry no tech support via PM's

message edited by wanderer


Report •

Related Solutions

#4
September 12, 2013 at 12:38:41
Do you have the correct netmask on your router? If that thinks it's on a /24 network then you would get the result you see. What about the server; presumably that has a fixed IP - does it have the correct netmask?

Report •

#5
September 15, 2013 at 05:41:08
I'd have to agree with wanderer on this one. I noticed in the OP's post the following:

The old scope is 10.192.30.21 - 10.192.30.126,subnet 255.255.255.128, default gateway 10.192.30.1

The new scope is 10.192.31.21 - 10.192.31.126, subet 255.255.255.128 but the default gateway that is shown on the clients is 10.192.31.1.

The second isn't a superscope of the first as it has the exact same netmask. In order to be a superscope, the netmask has to change as it does in wanderer's example:

original network:
If you were using 255.255.255.0 you would have 254 host ip addresses

Superscope of original network:
Now if you wanted to go up a notch and superscope you would use the same start of 10.192.30.x and use 255.255.254.0 which would give you a range of 10.192.30.0 - 10.192.31.255 which would provide 510 host ip addesses.

Note the subnet mask changes as you borrow bits from the network side and add them to the host side. As the mask changes, the number of available hosts increases with it.

At work our in-house wireless network was:
192.168.18.0/24
With the addition of pads and smart phones, we were running out of IP's on a daily basis. So we changed to:
192.168.18.0/22
Which greatly increased the number of available IP's.

If you're not sure about superscopes, there's plenty of available info on the web. WhatI can tell you is the OP's is not a superscope and won't work. Run that setup through a subnet calculator and then do the same with wanderer's suggested network and you'll see the difference.

It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.

***William Henley***


Report •

#6
September 15, 2013 at 18:34:09
Revised my sub netting notes and you were right. What i ended up doing was deleting the entire scope and redoing it. Changed the server subnet to 255.255.255.0 and the new scope runs from 10.192.30.1 - 10.192.30.200.

Of course had to reset some of the static ip's on the printers but everything is working as it should now and i have alot more room to add more devices.

Thank you guys so much for the help!


Report •

Ask Question