72 CHAPTER 4: NETWORK PROTOCOL OPERATION
By default, the switch does not learn gratuitous ARPs.
Configuring the Dynamic ARP Aging Timer
The following commands assign a dynamic ARP aging period to enable flexible
configurations. When the system learns a dynamic ARP entry, its aging period is
based on the currently configured value.
Perform the following configuration in system view.
By default, the aging time of the dynamic ARP aging timer is 20 minutes.
Displaying and Debugging ARP
After the previous configuration, execute display command in all views to display
the operation of the ARP configuration, and to verify the effect of the
configuration. Execute the debugging command in user view to debug the ARP
configuration.
By default, all ARP mapping entries of the Ethernet switch are displayed.
DHCP Relay Dynamic Host Configuration Protocol (DHCP) offers dynamic IP address
assignment. DHCP works in Client-Server mode. With this protocol, the DHCP
Client can dynamically request configuration information and the DHCP server can
configure the information for the Client.
The DHCP relay serves as conduit between the DHCP Client and the server located
on different subnets. The DHCP packets can be relayed to the destination DHCP
server (or Client) across network segments. The DHCP clients on different
networks can use the same DHCP server. This is economical and convenient for
centralized management.
Prevent the switch from learning gratuitous
ARPs
undo gratuitous-arp-learning
enable
Tabl e 67 Configure the Dynamic ARP Aging Timer
Operation Command
Configure the dynamic ARP aging timer arp timer aging aging-time
Restore the default dynamic ARP aging time undo arp timer aging
Tabl e 68 Display and Debug ARP
Operation Command
Display ARP mapping table display arp [ ip-address | [
static | dynamic ] [ { begin |
include | exclude } text ] ]
Display the current setting of the dynamic ARP
map aging timer
display arp timer aging
Enable ARP information debugging debugging arp { packet | status }
Disable ARP information debugging undo debugging arp { packet |
status }
Table 66 Learning Gratuitous ARPs
Operation Command