System information

Troubleshooting ISO CLNS 12-281
ISO CLNS: Host Cannot Access Hosts in Different Area
Router between hosts is
down
Step 1 Use the trace exec command to check connectivity between routers and the
source ES.
Sample Display:
The following display shows an example of ISO CLNS trace output:
router# trace
Protocol [ip]: clns
Target CLNS address: thoth
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Type escape sequence to abort.
Tracing the route to THOTH
(55.0006.0100.0000.0000.0001.8888.1112.1314.1516)
HORUS(55.0006.0100.0000.0000.0001.6666.3132.3334.3536) 32
msec ! 28 msec
28 msec !
2 ISIS(55.0006.0100.0000.0000.0001.7777.2122.2324.2526)
56 msec ! 80 msec
56 msec !
3 THOTH(55.0006.0100.0000.0000.0001.8888.1112.1314.1516) 80
msec ! 80 msec ! 8
Step 2
If the trace fails at a router, use the show clns neighbors exec command to see
which neighboring routers and ESs are recognized.
Step 3 If neighboring routers and end systems are up, perform one of the following
procedures:
• For ISO-IGRP, check the routing table and see whether the routes are being
learned. Use the show clns route exec command to display the routing tables.
• For IS-IS, check the LSP
2
database to see whether the links are being reported
in link state advertisements. Check the IS-IS routing table to see whether the
routes are being installed in the routing table. Use the show isis database
detail exec command to display the routing tables.
1 IGRP = Interior Gateway Routing Protocol
2 LSP = Link State Protocol
Possible Problem Solution