3Com 8807 Configuration Manual page 673

Configuring the
Dynamic ARP Aging
Timer
Adding/Deleting
Multicast ARP Ports
By default, the ARP mapping table is empty and the address mapping is obtained
through dynamic ARP.
Note that:
As long as a switch operates, its static ARP mapping entries remain valid unless
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you perform operations that make ARP invalid, such as change or remove
VLAN virtual interfaces, remove a VLAN, or remove an interface from a VLAN.
These operations cause the corresponding ARP mapping entries to be
automatically removed.
The vlan-id argument must be the ID of a VLAN that has been created by the
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user, and the Ethernet port specified behind this parameter must belong to the
VLAN.
The argument vpn-instance-name must be the VPN instance name of an
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existing MPLS VPN.
ARP map entries with port parameters can be configured on manually
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aggregated ports or static aggregated ports, but cannot be configured on
LACP-enabled dynamic aggregated ports.
If the mac-address of an ARP entry is a multicast MAC address, the system will
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assume this ARP entry to be multicast ARP entry.
Long static ARP can be configured only on manually aggregated ports, but not
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on static aggregated ported or dynamic aggregated ports.
For purpose of flexible configuration, the system provides the following
commands to assign dynamic ARP aging period. When the system learns a
dynamic ARP entry, its aging period is based on the current value configured.
Perform the following configuration in system view.
Table 609 Configure the dynamic ARP aging timer
Operation
Configure the dynamic ARP aging timer
Restore the default dynamic ARP aging time
By default, the aging time of dynamic ARP aging timer is 20 minutes.
The multicast ARP feature allows you to associate a common unicast route to a
Layer 2 multicast group, that is, add multiple outgoing ports for an outgoing ARP
packet so that the packet can be sent to multiple ports. As a result, a static
multicast ARP entry is generated. In brief, a multicast ARP entry is a static ARP
entry with a multicast MAC address, which may correspond to multiple ports.
According to the multi-port keyword in this command, the switch decides that
the port to be added is for a multicast ARP entry. Only one port can be added
every time the command is executed. If the multicast ARP entry does not exist, a
new multicast ARP entry is generated. If the multicast ARP entry exists and the
same egress exists, the switch will not add a multicast ARP port.
Perform the following configuration in system view.
Configuring ARP
Command
arp timer aging aging-time
undo arp timer aging
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