need advice on data center move, communication with both facilities during transition

Question

We are beginning the process of moving to a new facility. Office and warehouse operations will both be moving, and we must get shipping operations up and running at the new location while continuing to ship from the old location. Our contract with some third-party warehouse tenants requires two business day turnaround (only weekends and holidays excluded), so we can't have major downtime during the move.

We would like to keep our 172.16.60/61.xxx internal address space in use throughout the move. Is it possible to keep using this same internal range, and have our existing WatchGuard Firebox 520 and whatever router we get for the other location (preferably the same model) just treat both locations as one network, leaving our host IPs the same throughout the move?

Renumbering the servers when they move isn't a big deal, but our wireless terminals for order picking in the warehouse have fixed IPs (and a fixed IP, non-DNS reference to the host they speak with) and would be a massive undertaking to reconfigure when the servers move (each device would have to be reconfigured at least 2 times -- some when we start using them in the new building and the host is still here, all of them in both locations when the host moves to the new building, and the rest when they finally make the move to the new building). We're trying to avoid that if possible.

Answer 1

it is possible to have a VPN at layer2, which effectively bridges the two sites. you'll need quite good connectivity to make this work, i.e. relatively low latency and sufficient bandwidth to prevent congestion.

an example of how to do this would be using openvpn and the "tap" device, you could use pfSense firewall for this.

http://doc.pfsense.org/index.php/OpenVPN_Bridging

Answer 2

You have the right idea, kinda.

This is going to be a function of your business needs and available resources. If this is a straight relocation with no overlap between sites, you don't need to reconfigure your equipment. If you're going to be in a position where you're straddling both facilities, then more planning needs to take place.

So I've performed a good number of warehouse migrations, including RF picking/WMS solutions. In cases where I've needed to work out of two facilities, I verify internet communications and phones at the new facility first (a must), then establish a site-to-site VPN up between the two locations (usually working with Cisco ASA, but any hardware firewall/VPN solution will work).

This is a good time to determine which devices in your environment are DHCP-managed versus static. I'd plan on the IP renumbering for the static devices going to the new site. Let DHCP handle the rest.

For the RF guns/devices I use, I use these facility moves as a good opportunity to use DNS instead of hardcoded addresses. This will provide you much more flexibility in the future and eliminate the double-reconfiguration you speak of.