Information Technology Reference
In-Depth Information
Table12-3 ISO CLNS: Host Cannot Access Hosts on Local or Remote Network (continued)
Possible Problem
Solution
Router between
hosts is down
1.
Use the
trace
exec command to check connectivity between
routers and the source ES.
2.
If the
trace
fails at a router, use the
show clns neighbors
exec command to see which neighboring routers and ESs are
recognized.
Sample Display:
The following is sample output from the
show clns neighbors
command. This display is a composite of the
show clns
es-neighbor
and
show clns is-neighbor
commands:
router#
show clns neighbors
System Id SNPA Interface State
Holdtime Type Protocol
0000.0000.0007 aa00.0400.6408 Ethernet0 Init 277
IS ES-IS
0000.0C00.0C35 0000.0c00.0c36 Ethernet1 Up
91
L1 IS-IS
0800.2B16.24EA aa00.0400.2d05 Ethernet0 Up
29
L1L2 IS-IS
0800.2B14.060E aa00.0400.9205 Ethernet0 Up
1698
ES ES-IS
0000.0C00.3E51 *HDLC*
Serial1
Up
28
L2 IS-IS
0000.0C00.62E6 0000.0c00.62e7 Ethernet1 Up
22
L1 IS-IS
0A00.0400.2D05 aa00.0400.2d05 Ethernet0 Init 24
IS ES-IS
If neighboring routers and end systems are up, perform one
of the following procedures:
3.
For ISO-IGRP,
8
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,
9
check the LSP
10
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.
•
Route
redistribution
problem
Misconfigured route redistribution can cause connectivity
problems. For specific troubleshooting information, see the
section “ISO CLNS: Redistribution Causes Routing Problems”
later in this chapter.
1.
TCP/IP = Transmission Control Protocol/Internet Protocol
2.
ES = end system
3.
IS = intermediate system
4.
NSAP = Network service access point
5.
ES-IS = End System-to-Intermediate System
6.
MAC = Media Access Control
7.
NET = network entity title
8.
IGRP = Interior Gateway Routing Protocol
