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A10-2 893-741-B
AppleTalk
parameters a_router, zone, and node_id are hints for the Model 5390 server to use at startup
(AppleTalk-specific Model 5390 Parameters on page A10-3 describes these parameters).
The Model 5390 server behaves like an AppleTalk phase II end node. At startup, it listens for an
AppleTalk router in the startup network range and begins the process of finding its address. The
Model 5390 server selects as its A_Router the first router it detects broadcasting an RTMP Route
Data Request. It acquires an address within the A_Router’s net-range and then uses a ZIP GetNetInfo
and ZIP GetZoneList to find the network’s zones; otherwise The Model 5390 server obtains an
available address within the startup range.
The Model 5390 server also installs a net-range route and an AppleTalk default route from the
A_Router. If another router broadcasts an RTMP message, and its Ethernet address matches the
address defined in the Model 5390 parameter a_router, the Model 5390 server discards the current
router information and tracks to this new router. If the Model 5390 server does not hear from the
current A_Router for 50 seconds, it selects a new A_Router. This 50 second hold-down prevents
the Model 5390 server from bouncing between routers.
When ARA clients connect to the Model 5390 port, the node_id parameter acts as a hint to acquire
an address for the client. The Model 5390 server then installs a proxy aarp entry and the client’s
zone multicast address.