Windows 2003 server DHCP scope .. one problem

[geranimo666]

Hello all-

My class A (10.1.21.1 to 10.1.23.254) (subnet is 255.255.252.0) range has been entirely used up.. so I created a new scope. I just did a 10.1.24.1 to 10.1.27.254 range and made all the proper router, dns, wins etc settings as the other scope was set.. problem is that it won't lease out addresses at all.

The scopes status is "active" yet nothing.. no leases are nade. There are Cisco catalyst switch on all floors but no vlans have been created and it is essentially a flat network. Does anyone have any clues why it would not lease addresses.. can I just change my original scope to a different subnet to add more hosts or will I lose it and have to start over again if I try to reset it.. the subnet mask area is greyed out eitherway....

So does any one have any ideas why I can't lease addresses from this new scope?

thanks for any ideas..
geranimo

 

[WhoKilledKenny]

Looking at your IP Address Scheme and the 22-bit mask, the new range is a separate Network. Therefore I would assume that you would have to set up the router "ip-helper" address to allow DCHP broadcasts from the new subnet to the subnet where your DHCP server is located. And you should set up VLANS on the switches.

Jesse Hamrick

http://www.powershellpro.com

 

[lhuegele]

You could also change your subnetmask to include more addresses and modify the existing DHCP scope.

 

[geranimo666]

Thanks lhuegele,

But does this mean that I need to make equivalent changes on all my routers and(or) switches? I could easily just make the subnet mask 255.255.250.0 and allow for more client addresses but just wonder if the routers and switches need modifying as well. It is a flat network..

thanks for any info
geranimo

 

[geranimo666]

Thanks lhuegele,

But does this mean that I need to make equivalent changes on all my routers and(or) switches? I could easily just make the subnet mask 255.255.250.0 and allow for more client addresses but just wonder if the routers and switches need modifying as well. It is a flat network..

thanks for any info
geranimo

 

[lhuegele]

Hi Geranimo, since you have a flat network (which I take to mean that you don't have any managed switches) then you shouldn't have anything to change on your switches. At most you may just have to reset them so they can flush their arp cache.

The router might be a different story. You may need to adjust the configuration on your router. I don't remember having to reconfigure our router when we expanded our scope a few years ago. Our router only sat between our network and the internet connection so it really didn't impact us one way or the other if my memory serves me correctly, but I could be wrong.

Good luck,

 

[geranimo666]

hi lhuegele,

well there are roughly 350 users within the building from end to end and on two floors, there are roughly 7 cisco switches deployed (layer 2), and each config I look at shows that ports are all dumped in vlan 1 (management vlan which is default).

so if all I need to do is flush arp tables in the switches, that would be great and easy... it's the alternate affect I'm thinking that would be a real pain in the &ss to handle, which is to create vlans and route between all the swithces.. I wouldn't even know where to begin doing this for a new 10.1.24.x range based on 7 switches.

I'll keep my fingers crossed,
geranimo

 

[lhuegele]

Well good luck and let us know how everything turns out.

 

[WhoKilledKenny]

Also, check the router Interface for the 10.1.X.X network and verify its config. If it is 10.0.0.0/8 then you can make any changes to the subnet mask as all 10.X.X.X traffic is set-up to route through that interface. If the config is 10.1.21.0/22 the you will have change the interface to reflect new subnet mask. If you are using a static routing table you will also need to add entries to the routing table.

Jesse Hamrick

http://www.powershellpro.com