Netgear GS728TPP – 28PT GE POE+ SMART SWITCH Guia Do Administrador
Configuring Routing
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GS752TP, GS728TP, and GS728TPP Gigabit Smart Switches
Configure ARP
The Address Resolution Protocol (ARP) associates a Layer 2 MAC address with a Layer 3
IPv4 address. The switch software features both dynamic and manual ARP configuration.
With manual ARP configuration, you can statically add entries to the ARP table.
IPv4 address. The switch software features both dynamic and manual ARP configuration.
With manual ARP configuration, you can statically add entries to the ARP table.
ARP is a necessary part of the Internet Protocol (IP) and is used to translate an IP address to
a media (MAC) address, defined by a local area network (LAN) such as Ethernet. A station
needing to send an IP packet must learn the MAC address of the IP destination, or of the
next hop router, if the destination is not on the same subnet. Learning is achieved by
broadcasting an ARP request packet, to which the intended recipient responds with a unicast
needing to send an IP packet must learn the MAC address of the IP destination, or of the
next hop router, if the destination is not on the same subnet. Learning is achieved by
broadcasting an ARP request packet, to which the intended recipient responds with a unicast
ARP reply containing its MAC address. Once learned, the MAC address is used in the
destination address field of the Layer 2 header prepended to the IP packet.
The ARP cache is a table maintained locally in each station on a network. ARP cache entries
are learned by examining the source information in the ARP packet payload fields,
regardless of whether it is an ARP request or response. Thus, when an ARP request is
broadcast to all stations on a LAN segment or virtual LAN (VLAN), every recipient has the
opportunity to store the sender’s IP and MAC address in its respective ARP cache. The ARP
response, being unicast, is normally seen only by the requestor, who stores the sender
information in its ARP cache. Newer information always replaces existing content in the ARP
cache.
are learned by examining the source information in the ARP packet payload fields,
regardless of whether it is an ARP request or response. Thus, when an ARP request is
broadcast to all stations on a LAN segment or virtual LAN (VLAN), every recipient has the
opportunity to store the sender’s IP and MAC address in its respective ARP cache. The ARP
response, being unicast, is normally seen only by the requestor, who stores the sender
information in its ARP cache. Newer information always replaces existing content in the ARP
cache.
The NETGEAR switches support 1024 ARP entries in switch mode and approximately 100 in
router mode. These entries include dynamic and static ARP entries.
router mode. These entries include dynamic and static ARP entries.
Devices can be moved in a network, which means the IP address that was at one time
associated with a certain MAC address is now found using a different MAC address, or might
have disappeared from the network altogether (that is, it has been reconfigured,
disconnected, or powered off). This leads to stale information in the ARP cache unless
entries are updated in reaction to new information seen on the network, periodically
refreshed to determine if an address still exists, or removed from the cache if the entry has
not been identified as a sender of an ARP packet during an ageout interval, specified through
configuration.
associated with a certain MAC address is now found using a different MAC address, or might
have disappeared from the network altogether (that is, it has been reconfigured,
disconnected, or powered off). This leads to stale information in the ARP cache unless
entries are updated in reaction to new information seen on the network, periodically
refreshed to determine if an address still exists, or removed from the cache if the entry has
not been identified as a sender of an ARP packet during an ageout interval, specified through
configuration.
From the ARP menu, you can access features described in the following sections:
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