Novell NETWARE 6-DOCUMENTATION Manual page 1749

Figure 6 IAMG Implementation
Customer
Network
00001234
NetWare
Workstation
38
Internetwork Packet Exchange
Gateway Address
01014000
IPX Address
Mapping Gateway
NetWare
File Server
The IAMG allows multiple gateways to be connected between the customer
network and backbone network in parallel. All such gateways on a customer's
network share a single gateway address. If a gateway receives a packet from
the backbone network with an unknown mapping on the gateway network, the
packet is forwarded to all other IAMGs advertising the same gateway address.
If necessary, the packet is split into multiple segments using the IPX
fragmentation module so that the packet can be forwarded with a new header
attached.
If not all gateways support the IPX fragmentation specification, the IAMG is
designed to allow the gateways to run in parallel. In this automatic mode of
operation, some packets might be lost during the learn cycle. When the
gateway that created the mapping receives the forwarded data packets from
the backbone, an update reporting the mapping is returned to the gateway that
initially received the packet. Because more packets probably will follow, the
gateway learns the new mapping.
The IAMG discards any packet destined for the gateway that has the broadcast
node address so that outside clients cannot cause an excessive number of
broadcasts within a network. NetBIOS broadcasts (packet type 20) cannot be
used on a network attached to an interface that has the IAMG enabled.
Broadcasts to networks other than the gateway address are allowed.
Backbone Network
Backbone
Service
Backbone
Services