
AppleTalk Implementation Notes
117366-A Rev. A 2-33
A larger update rate (for example, 1 hour) causes routers to converge less quickly,
making changes to the network appear less quickly in the Chooser application.
Zones may still appear in the Chooser even though their associated networks are
no longer reachable across the tunnel. Also, new network information does not
become accessible until the update occurs. This could prove frustrating for some
users.
For information on editing the Update Rate parameter, refer to “Editing AURP
Parameters” in Chapter 4.
AURP uses the following packets to update its AppleTalk routing information:
• Routing Information Update (RI-Upd)
• Routing Information Request (RI-Req)
• Routing Information Response (RI-Rsp)
• Routing Information Acknowledgment (RI-Ack)
• Zone Information Request (ZI-Req)
• Zone Information Response (ZI-Rsp)
Setting the Last Heard From Timeout
The AppleTalk router uses the Last Heard From Timeout parameter to periodically
check that the other end of the connection is up. If the router does not receive an
RI-Upd, RI-Rsp, or ZI-Rsp packet within the Last Heard From Timeout period, it
sends a Tickle Request and expects a Tickle Acknowledgment.
If the router does not receive the acknowledgment within the Command Timeout
period, the router repeats its Tickle Request up to the Command Retries amount.
If the router does not receive an acknowledgment, the connection is closed.
A large Last Heard From Timeout value may postpone the discovery of a failed
connection by an exterior router. If you are using AURP to create an AppleTalk
wide area network, you may want to increase the value to an hour (3600 seconds)
if the WAN is relatively stable. However, if you know a network may be unstable,
you may want to decrease this value to as little as 30 seconds to ensure that you
are aware of any disruptions in service.
For information on editing the Last Heard From Timeout parameter, refer to
“Editing AURP Parameters” in Chapter 4.
Comentarios a estos manuales