Information Technology Reference
In-Depth Information
ISO CLNS: Host Cannot Access Hosts on Local or Remote Network
Symptom:
Hosts cannot communicate with other hosts. Hosts might be located on the local or a remote
network. Connections to some hosts on a network might be possible, whereas connections to other hosts
on the same network fail.
Table 12-3 outlines the problems that might cause this symptom and describes solutions to those
problems.
Table12-3 ISO CLNS: Host Cannot Access Hosts on Local or Remote Network
Possible Problem
Solution
Missing or
misconfigured
default gateway
specification
Determine whether a default gateway is specified in the
adjacency table of the host attempting to make a connection.
Use the following UNIX command:
1.
host%
netstat -rn
Check the output of this command for a default gateway
specification.
Syntax Description:
netstat
—Displays protocol statistics and current TCP/IP
1
network connections
•
r
—Displays the contents of the routing table
•
n
—Displays addresses and port numbers in numeric form
•
If the default gateway specification is incorrect, or if it is not
present at all, you can change or add a default gateway using
the following UNIX command at the local host:
2.
host%
route add default
address
1
where
address
is the IP address of the default gateway (the router
local to the host). The value 1 indicates that the specified
gateway is one hop away.
It is recommended that you specify a default gateway as part
of the boot process. Specify the ISO CLNS address of the
gateway in the following UNIX host file:
3.
/etc/defaultrouter
This filename might be different on your UNIX system.
End system has no
Level 1 router
1.
Use the
show clns neighbors detail
privileged exec
command to show all ESs
2
and ISs
3
to which the router is
directly connected.
2.
Make sure there is at least one Level 1 router on the same
network as the end system.
