Netgear GC108P User Manual - Page 223

Insight Managed 8-Port Gigabit (Hi-Power) PoE+ Smart Cloud Switch with NETGEAR FlexPoE Power 7. Select the check box next to each route to remove. 8. Click the Delete button. The static route is deleted. Configure ARP The address resolution protocol (ARP) associates a layer 2 MAC address with a layer 3 IPv4 address. The switch support both dynamic and manual ARP configuration. With manual ARP configuration, you can statically add entries into the ARP table. ARP is a required 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 an Ethernet network. A device that must send an IP packet must learn the MAC address of the IP destination, or if the destination is not on the same subnet, of the next hop router. The device achieves this by broadcasting an ARP request packet, to which the intended recipient responds by sending an ARP unicast reply that contains 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 device on the 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. In this way, when an ARP request is broadcast to all stations on a LAN segment or virtual LAN (VLAN), each recipient can store the sender's IP address and MAC address in its ARP cache. The ARP response, which is a unicast reply, is normally detected only by the device that sends the ARP request. That device stores the sender's information in its ARP cache. Newer information always replaces existing content in the ARP cache. If you move a device in the network, the device's MAC address can become associated with another IP address. Or if you reconfigure, disconnect, or power off the device, the device's IP address can disappear from the network altogether. To prevent such situations from causing information in the ARP cache to become outdated, each device on the network periodically updates the entries in its ARP cache with new information from the network. On the switch, you can set the ageout interval for ARP entries from 15 to 21600 seconds. When the ageout interval is reached, ARP entries for which the switch did not receive an ARP reply are removed form the switch ARP cache. The switch supports 512 ARP entries, which include dynamic and static ARP entries. Configuring Routing 223 User Manual