Hitachi GR2000 Series - Manual (Page 189)

Troubleshooting
GR2K-GA-0015 7-23
Ver. 07-02
7.5 Communication Failure in IPv4 Network
7.5.1 Communication cannot be done or communication is disconnected
The following is considered as the main cause of a communication trouble that
occurs in an IPv4 network that uses the router.
1. Configuration information related to IP communication changes
2. Network configuration changes
3. Network equipment failure
For the first two factors, check the difference in IP communication and network
configuration information before and after the change to see whether there is any
reason for interrupted communication.
This section explains the procedure for determining failure location and cause, and
for resolving the failure, in the event of correct IP communication and network
configuration information. To detect and isolate the failure, see the troubleshooting
the flowchart Figure 7-10 below.