System information

Troubleshooting AppleTalk
Book Title
9-190
The following is sample output from the show appletalk interface command when a configuration
mismatch exists:
Ethernet 0 is up, line protocol is up
AppleTalk routing disabled, Port configuration mismatch
AppleTalk cable range is 4-5
AppleTalk address is 4.252, Valid
AppleTalk zone is “Maison Vauquer”
AppleTalk port configuration conflicts with 4.156
AppleTalk discarded 8 packets due to input errors
AppleTalk discarded 2 packets due to output errors
AppleTalk route cache is disabled, port initializing
Line 2 of the command output shows that routing has been disabled due to a port configuration
mismatch. Line 6 indicates the AppleTalk address of the conflicting router.
You can also display the NBP registered name of the conflicting router, which can simplify
resolution of a port mismatch problem. To see registered NBP names, enable the
appletalk name-lookup-interval global configuration command. This causes the show
appletalk interface exec command output to display nodes by NBP registration name.
Phase 1 and Phase 2 Rule Violations
When Phase 1 and Phase 2 routers are connected to the same internetwork, the internetwork
specifications must conform to two rules:
• There can be no “wide” cable range specifications in the Phase 2 extended portion of the
internetwork. That is, no cable ranges can span more than a single (unary) network number. For
example, the cable ranges 2–2, 9–9, and 20–20 are all acceptable. The cable ranges 10–12 and
100–104 are not acceptable.
• Multiple zones cannot be assigned to unary cable ranges.
If these rules are not followed, connectivity between the nonextended and extended portions of an
internetwork becomes degraded and might be lost. In particular, services located on nonextended
networks using Phase 1 routers will not be visible on the other side of the Phase 1 router.
Note On Cisco routers, Phase 1 refers to the router Ethernet interfaces being configured with a
single network address and Ethernet I encapsulation, instead of with a cable-range and Ethernet
SNAP encapsulation. A Cisco router running Software Release 8.2 or later is a Phase 2–compliant
router regardless of how the interfaces are configured.
Another Phase 1 and Phase 2 issue is the handling of NBP packets. Phase 1 AppleTalk has three
types of NBP packets, and Phase 2 AppleTalk has four types of NBP packets. This difference can
lead to communication problems between Phase 1 and Phase 2 routers. Table 9-3 lists the NBP
packet types for AppleTalk Phase 1 and Phase 2.
Table 9-3 Comparison of Phase 1 and Phase 2 NBP Packet Types
Phase 1 NBP Packet Phase 2 NBP Packet
BrRq (Broadcast Request) BrRq (Broadcast Request)
— FwdReq (Forward Request)
LkUp (Lookup) LkUp (Lookup)
LkUp-Reply (Lookup Reply) LkUp-Reply (Lookup Reply)