Alaxala AX2500S, Руководство по устранению неисправностей

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3 Troubleshooting Functional Failures During Operation
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
See (8) Checking the filtering and QoS configuration information .
(7) Checking the DHCP server configuration information
If IP addresses for clients are assigned by the DHCP server functionality on the Switch, the
IP addresses might have not been properly assigned. Check whether the setting conditions
for the DHCP server functionality in the configuration are correct. For details about the
procedure, see
3.6.2 Communication failures occurring when the DHCP server is used .
(8) Checking the filtering and QoS configuration information
Certain packets might have been discarded by filtering or packets might have been
discarded by the QoS control shaper.
Make sure that the setting conditions for filtering and QoS control in the configuration are
correct, and that the shaper is used appropriately in the system configuration. For details
about the procedure, see
3.15.1 Checking the filtering and QoS control configuration
information .
3.6.2 Communication failures occurring when the DHCP server is used
There are three probable causes for problems such as disabled address distribution to
clients that might occur during communication with the DHCP server:
1. A configuration is set incorrectly.
2. The network configuration is changed.
3. The DHCP server fails.
First, check for cause 1. Described below are likely examples of incorrect configuration. For
cause 2, check the differences in the network configuration before and after the change to
uncover any cause that could disable communication. If you have checked the client and
server settings (such as network card settings and cable connections) and concluded that
cause 3 applies (for example, the configuration and network configuration are correct, but
IP communication is not possible due to disabled allocation of IP addresses to clients),
see
(b) Checking the operation log and interface through (d) Checking the filtering and QoS
control configuration information .
(a) Checking the configuration
It can be assumed that IP addresses cannot be allocated to clients if the resources on the
DHCP server are configured incorrectly. To check the configuration, do the following:

In the configuration, make sure there is an ip dhcp pool setting that contains the
network setting for the IP addresses to be assigned to the DHCP clients.

In the configuration, make sure the number of IP address pools to be assigned to a
DHCP client is larger than the number of concurrently used clients set in the ip dhcp
excluded-address
configuration command.

When an external DHCP server is used, check the setting on the device to be used
as a DHCP relay agent.
(b) Checking the operation log and interface
One probable cause of disabled assignment of IP addresses to clients is that
communication between the client and the server has been disabled. Check the operation
log displayed by the Switch or use the
show ip interface operation command to check
whether the interface status is Up or Down . For details about the procedure, see 3.4 Network
interface communication failures .
(c) Identifying the range for a failure (from the Switch)
If a failure has not occurred on the Switch, a failure might have occurred somewhere on the
route between the Switch and the remote device. To identify the range for a failure in order