Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
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No. Items to check and commands Action
binding
operation command to
check the time that the database
was saved.
If the time displayed for Last succeeded time is too old, continue
with No. 3.
2 Use the show running-config
operation command to check the
configuration.
If ip dhcp snooping database url mc is set, continue with No.
3.
If ip dhcp snooping database url mc is not set, set the ip
dhcp snooping database url mc <saved-file-name>
configuration command.
3 Use the show logging operation
command to check the operation log
for restoration of the binding
database.
If It was not able to restore binding database from
mc.<retry> <reason> has been recorded, restoration from the
memory card has failed.
If MC is not inserted. is displayed for <reason>, the memory
card might not be inserted or might not be fully inserted.
If the memory card is not inserted, insert it.
If the memory card is inserted, remove the memory card, and then
insert it again until you hear it clicks. (When inserting the memory
card, do not push it with force or flick it.)
Go to No. 4.
If MC file is not found. is displayed for <reason>, the
inserted memory card does not contain the file, or the memory
card contains a file whose name has not been specified by the ip
dhcp snooping database url mc configuration command.
Replace the memory card with the one on which the binding
database was saved.
Go to No. 4.
If the displayed <reason> is not any of the above, the restoration
from the memory card has failed.
Go to No. 4.
4 Restart the switch.
If MC file is not reading. is displayed for <reason>, the file
saved on the memory card or the memory card might itself be
corrupted.
Clear the IP addresses on the DHCP client terminal. (In Windows,
in the Command Prompt window, execute ipconfig /release,
and then ipconfig /renew.)
3.5.5 Multicast forwarding by IGMP snooping is not possible
If multicast forwarding is not possible when IGMP snooping is used, use the following
analysis flowchart to determine the problem and isolate the cause.