Migration Agent Interconnecting IP and IPX Nodes
The Migration Agent is a tool that enables communication between IPX and IP systems. It also enables you to create an IP backbone that interconnects IPX segments. Use this tool when you want to migrate systems from IPX to IP in a phased manner without losing connectivity.
The MA takes the IPX requests, which are in an IP packet, and tunnels the IP packet in an IPX wrapper to be sent out on the IPX wire. The opposite occurs when an IPX packet is sent across the IP backbone.
In previous versions of NetWare, IP access was provided on NetWare networks with NetWare/IPTM. NetWare/IP took every packet (all were IPX packets) and tunneled each in an IP wrapper. This kind of IP tunneling is no longer needed, because tunneling has been reversed in NetWare 6---instead of tunneling IP packets in IPX with NetWare/IP, IPX packets are now tunneled in IP packets with the Migration Agent. Now, only the few IPX requests require tunneling, providing better throughput and efficiency.
The MA serves as a router between the IPX network and the virtual IPX network segment created by the IPX Compatibility drivers as illustrated in Figure 4.
Figure 4
Migration Agent Interconnecting IP and IPX Nodes
More than one MA is needed to enable resiliency and load-sharing, or when you want to interconnect IPX segments with an IP backbone. Figure 5 shows two Migration Agents interconnecting two IPX segments.
Figure 5
Migration Agents Interconnecting IPX Segments
The MA is supported only at the NetWare server. The MA is enabled by loading the IPX Compatibility driver (scmd.nlm) with the Migration Agent option. The Migration Agents are then used by the IP systems on the network.If more than one MA is needed, all Migration Agents must be able to access the same IPX networks or be able to exchange IPX network information. Migration Agents exchange IPX network information by invoking the IP Backbone Support feature, which is accomplished by loading the scmd.nlm with the backbone support options.
To set up an MA, the Service Location Protocol must be enabled across the networks, because Migration Agents are dependent on the capabilities of SLP.
The IPX Compatibility drivers are capable of dynamically discovering Migration Agents, but you can also choose to statically configure the address of the MA if more control is desired.The IPX Compatibility driver will discover an MA if it is in the same IP network, and will give preference to an MA within the local IP subnet. The address of the MA must be specified in IP systems that reside in different IP networks.The address of the MAcan be configured either by manipulating the local configuration files or by disseminating the information through DHCP.