System information

Troubleshooting AppleTalk 9-193
AppleTalk: No Devices in Chooser
AppleTalk: No Devices in Chooser
Symptom: Zones appear in the Chooser, but when a service (such as AppleShare) and a zone are
selected, no devices appear in the device list.
Table 9-5 outlines the problem that might cause this symptom and describes solutions to that
problem.
Table 9-5 AppleTalk: No Devices in Choose
ZIP storm A ZIP storm occurs when a router propagates a route for which it currently has no
corresponding zone name; the route is then propagated by downstream routers.
Note: Cisco routers provide a firewall against ZIP storms in the internetwork. If a
Cisco router receives a routing update from a neighbor, it does not propagate that
new route until it receives the accompanying zone name.
Step 1 Use the show appletalk traffic command and check the field showing the
number of ZIP requests.
The following example is output from the show appletalk traffic
command:
Router#sh apple traffic
[...]
ZIP: 44 received, 35 sent, 6 netinfo
[...]
Router#
Compare this output with the output shown by the command 30 seconds
later.
Step 2 If the traffic counters for ZIP requests are incrementing very rapidly (by
more than 10 every 30 seconds), a ZIP storm is probably occurring.
Use the debug apple zip privileged exec command to identify the
network for which the zone is being requested by neighboring routers.
You can also use the show apple private exec command to check the
number of pending ZIP requests.
Step 3 Identify the router that injected the network number into the internetwork
(and that is causing the excessive ZIP traffic). The show appletalk traffic
and show appletalk route exec commands provide information that can
help you find the suspect router.
ZIP storm For example, you can use the show appletalk route exec command to
view the AppleTalk routing table. Check whether a network shows up in
the routing table, even though the display indicates that no zone is set.
If you find a network for which no zone is set, a node on that network is
probably not responding to ZIP requests, resulting in the ZIP storm.
Step 4 Determine why the node is not responding to ZIP requests. Access lists or
other filters might be the cause. ZIP storms can also result from a defect in
the software running on the node. Contact the vendor to determine
whether there is a known problem.
Too many zones in
internetwork
The Chooser in System 6 can display only a limited number of zones, which
presents problems in large internetworks that have many zones.
If the Macintosh is running a version of System 6, upgrade it to System 7 or
System 7.5.
1 RTMP = Routing Table Maintenance Protocol
Possible Problems Solution