Problems Related To Arp; Communication Problems Due To Causes Other Than Dhcp And Arp - Alaxala AX6700S series Troubleshooting Manual

3. Troubleshooting Functional Failures During Operation
No.
5 Make sure that the lease time of the IP addresses
distributed to the DHCP clients is longer than the
wait time for saving the database.
6 Other cases

3.27.3 Problems related to ARP

If ARP packets are discarded, IPv4 communication is not possible. A probable cause of ARP
packets being discarded is dynamic ARP inspection. Isolate the cause of the problem according to
the failure analysis method described in the following table.
Table 3-86: Failure analysis method for problems caused by dynamic ARP inspection
No.
1 Check the DHCP snooping configuration.
2 Execute the
show ip arp inspection
command to check the operation
statistics
status of dynamic ARP inspection.
3 Execute the
show ip dhcp snooping binding
command, and make sure that the binding
information is present for the device on which
communication is not possible.
4 Other cases

3.27.4 Communication problems due to causes other than DHCP and ARP

If terminal filters are enabled, all packets are discarded, except DHCP and ARP packets from
devices not in the binding information. Isolate the cause of the problem according to the failure
analysis method described in the following table.
Table 3-87: Failure analysis method for problems caused by terminal filters
No.
1 Check the DHCP snooping configuration.
158
Items to check
Items to check
Items to check
Action
If the lease time is shorter, the lease of the IP addresses
might expire before the binding database is completely read
in.
Use the
ip dhcp snooping database write-delay
configuration command to shorten the wait time for saving
the database on the Switch. Alternatively, on the DHCP
server, extend the lease time of the IP addresses.
If there is no problem, go to No. 6.
If there is no problem when the binding database is saved in
the flash memory, but the binding information cannot be
inherited when the database is saved in a memory card,
replace the memory card.
Note that if you are planning long-term operation, save the
binding database in a memory card.
Action
See 3.27.1 Problems related to DHCP, and make sure
DHCP snooping is operating normally.
If there is no problem, go to No. 2.
If a port is displayed as an untrusted port at which dynamic
ARP inspection is enabled and the port is the one at which
IPv4 communication is not possible, go to No. 3.
If the target device is connected to another port, dynamic
ARP inspection is not enabled for the device. Check the
network configuration and the settings of the device on
which IPv4 communication is not possible, and if there is no
problem, go to No. 4.
If the binding information is not present and the target
device has a fixed IP address, set the
configuration command. If the binding information is not
present and the target device obtains an IP address by
DHCP, obtain an IP address again.
If any of the above actions do not resolve your problem,
check other functionality used in the device according to
this manual.
Action
See 3.27.1 Problems related to DHCP, and make sure
DHCP snooping is operating normally.
ip source binding