21 CONFIGURING IP APPLICATION
This chapter contains information on the following topics:
■Configure Address Resolution Protocol (ARP)
■Configure Domain Name Resolution (DNS)
■VLAN Configuration
■DHCP Server Configuration
■Configure DHCP Relay
■Configure Network Address Translation (NAT)
Configure Address
Resolution Protocol
(ARP)
ARP is mainly used for resolution from IP address to Ethernet MAC address.
Normally, dynamic ARP is used to resolve the mapping relation from the IP address
to the Ethernet MAC address. The resolution is completed automatically. At
present, the number of dynamic ARP mapping table items supported by the 3Com
Router series is up to 2000.
To configure ARP, carry out the following steps:
1Manually add/delete static ARP mapping table item
In some special cases, for example, the LAN gateway is assigned with a fixed IP
address and bound to a specific network adapter, so that packets to this IP address
can only go out via this gateway. While filtering illegal IP addresses if they are
bound to a non-existing MAC address, it is necessary for user to configure
mapping items in the static ARP table manually.
In the system view, configure the following commands.
Tabl e 357 Define a static ARP mapping
2Manually add/delete dynamic ARP mapping table item
In the system view, configure the following commands.
Tabl e 358 Define a static ARP mapping
Operation Command
Manually add static ARP mapping table item arp static ip-address
mac-address
Manually delete static ARP mapping table item undo arp static ip-address
Operation Command
Manually add dynamic ARP mapping table item arp dynamic ip-address
mac-address
Manually delete dynamic ARP mapping table
item undo arp dynamic ip-address