Migrating to IP

Follow these steps to wean your NetWare network off IPX/SPX and make the move to TCP/IP.

By LAURA CHAPPELL
Network World, 10/18/99

For diehard fans of Novell's IPX/SPX protocol who have been putting off the inevitable upgrade to TCP/IP, this guide to migration makes the process as painless as possible.

If you're upgrading to NetWare 5 or have already deployed it, now is an opportune time to migrate to TCP/IP. Unlike previous versions of the network operating system, NetWare 5 supports pure IP and even makes it the default network protocol.

To be sure, the job is time-consuming and requires organization and persistence. However, following the seven basic migration steps outlined here will help preserve your sanity.

You'll also find tips from Steve Williams, network administrator for the state of New Mexico in Santa Fe. Williams recently migrated the state's general services division network from NetWare 4.11 to NetWare 5, then made the switch from IPX to IP.

The steps

1. Design and implement a TCP/IP network if your company doesn't already have one in place. The IP addressing system should provide Internet access and lots of room for growth. You may want to use a network address translation system to simplify addressing for large, heavily routed networks.

Compared to IPX/SPX, the TCP/IP protocol stack is more susceptible to security breaches because of its open, trusting nature. Consider implementing a firewall and begin studying up on IP-related security issues.

2. Use a protocol analyzer to identify IPX-dependent applications wherever possible. Most IPX/SPX and SAP-dependent applications will work because NetWare 5 has a transparent Compatibility Mode element that supports the applications through protocol encapsulation and unique discovery spoofing mechanisms.

3. Update Novell Directory Services (NDS) and back up everything. Most likely, at some point in the migration you'll have older NetWare 4.X servers co-existing with NetWare 5 servers. Williams recommends upgrading the network to NetWare 4.11 before installing NetWare 5 anywhere to ensure compatibility between directory services versions.

Before you even consider which server to upgrade to NetWare 5, first ensure that NDS is healthy. Check the error logs and consoles for any messages alerting you to a problem. Eradicate all NDS problems before starting the migration and check for any NDS faults once the upgrade to NetWare 5 is complete. For example, make sure your servers can communicate with each other and complete NDS updates properly.

4. Implement a dual-stack server environment. This is necessary to support IPX and IP clients throughout the transition period. Williams advises against rushing the switch to pure IP.

"Keep a dual stack running as long as needed," he says.

Once you're comfortable that TCP/IP is running properly, you're ready for the next step.

5. Switch clients over to pure IP. If the clients already support TCP/IP, remove IPX/SPX. Otherwise, you'll need to load TCP/IP and then remove IPX/SPX to make them pure IP clients.

In order to support your legacy applications, select the "IP and IPX" radio button on the NetWare 5 client install. This provides backward-compatibility with IPX Compatibility Mode Driver (CMD), which lets the client encapsulate IPX-dependent communications inside IP packets. CMD also provides an IP-only method of discovery for backward-compatibility, as well.

6. Switch NetWare servers over to pure IP. Novell recommends that you start with the root master, which contains the master replica of the partition. Williams suggests bringing up a clean computer with NetWare 4.11, making it the root master, letting NDS stabilize for a week, and then upgrading that server first.

7. Clean up or replace any remaining IPX-dependent applications crossing the wire. If you've already migrated the clients and servers to IP only, NetWare will encapsulate the IPX packets and you'll see IPX and IP headers. Although this CMD function should work transparently, end users may notice better performance from applications that run over the native IP stack.

If you have small WAN sites, Williams suggests you upgrade or replace the server with NetWare 5. Next, migrate all remote clients to the latest version of the NetWare 5 client while the IPX network is still running. Select the IP and IPX radio button for backward-compatibility while needed. Finally, "drop IPX on the WAN link on a Friday morning and see who calls," Williams says. "If it is a big WAN site or if you had too many calls, then you need to do a WAN IP translation backbone between the sites."

A WAN IP translation backbone encapsulates IPX traffic in IP so you can run it across the WAN. Use this temporary solution until you can isolate and remove all IPX-dependencies.

"Do not get in a rush, and do not let others rush you," Williams says. "Make written plans and log actions taken, so if you need to backtrack you can."

There is no doubt that TCP/IP is the protocol stack that offers the greatest capability, flexibility and growth potential for today's networks. So although the migration process may be tough, it should be well worth it.