I work for a very old company that owns a class B IP range. I've been given the task of moving our lan addresses to class C.
I was going to start with the following approach;
- create a new dhcp pool on existing win 2008 server with class C range
- create new corresponding vlan/subnet on switches with dhcp relay
- create new corresponding svi for the clan
- update GRE/ASA configs accordingly
Does this seem like the correct approach?
It is my understanding that dhcp "just works". So the two separate vlans/subnets should only get dhcp leases from their corresponding pool on my win 2008 server?
Thanks in advance.
Assuming that the DHCP scopes are configured correctly then yes each vlan should get addresses from its own scope.
In general the approach that you describe sounds reasonable. I am not entirely clear what is involved when you talk about GRE/ASA. Would providing for address translation for the new subnet be part of that? And I do not know enough about your network to know whether there need to be changes in routing protocols to create routing table entries for the new subnet.
The ASA/GRE part refers to our wan. Basically traffic flows like this;
Workstations > Core > ASA > INTERNET
Workstations > Core > ASA > GRE > INTER-OFFICE
We have GRE for VPN tunnels.
I did a major IP address change at a large hospital. Your plan should work fine. It's pretty easy to get the endpoints migrated too. Just copy paste on the interface something like:
switchport access vlan
The shut/no shut will cause the endpoint to send a dhcp request and get an address on the new subnet.