H3C SOHO IE4300, Command Reference Manual

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2
Predefined user roles
network-admin
Usage guidelines
This feature enables a device to log ARP events when ARP cannot resolve IP addresses correctly.
The log information helps administrators locate and solve problems. The device can log the following
ARP events:
•
On a proxy ARP-disabled interface, the target IP address of a received ARP packet is not one of
the following IP addresses:

The IP address of the receiving interface.

The virtual IP address of the VRRP group.
•
The sender IP address of a received ARP reply conflicts with one of the following IP addresses:

The IP address of the receiving interface.

The virtual IP address of the VRRP group.
The device sends ARP log messages to the information center. You can use the info-center
source
command to specify the log output rules for the information center. For more information
about information center, see Network Management and Monitoring Configuration Guide .
The device can generate a large number of ARP logs. To conserve system resources, enable ARP
logging only when you are auditing or troubleshooting ARP events.
Examples
# Enable ARP logging.
<Sysname> system-view
[Sysname] arp check log enable
arp mac-interface-consistency check enable
Use
arp mac-interface-consistency check enable
to enable interface consistency
check between ARP and MAC address entries.
Use
undo arp mac-interface-consistency check enable
to disable this feature.
Syntax
arp mac-interface-consistency check enable
undo arp mac-interface-consistency check enable
Default
Interface consistency check between ARP and MAC address entries is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
In an unstable network, the receiving interface for packets from a user might change. The interface in
the MAC address entry can be updated immediately while the interface in the ARP entry cannot. In
this case, the packets matching the ARP entry will be sent out of an incorrect interface. To solve this
problem, you can use this feature to periodically check the interface consistency between the ARP
and MAC address entry for a user. If the interfaces are not the same, ARP sends ARP requests in
the VLAN of the ARP entry and updates the entry with the ARP reply receiving interface.