PointRed Telecom Ltd. MCRD-2458 Manuale Utente
M i c r o R e d & M i c r o V i e w N M S U s e r M a n u a l v 1 . 0
Page 139
Figure 142. Interface Packet Statistics
12.4.
Viewing the ARP Table
The ARP Entries tab contains the ARP (Address Resolution Protocol) table of the
currently selected MicroRed node.
currently selected MicroRed node.
On a single physical network, individual hosts are known on the network by their
physical hardware address. Higher-level protocols address destination hosts in
the form of a symbolic address (IP address in this case). When such a protocol
wants to send a datagram to destination IP address w.x.y.z, the device driver
does not understand this address.
physical hardware address. Higher-level protocols address destination hosts in
the form of a symbolic address (IP address in this case). When such a protocol
wants to send a datagram to destination IP address w.x.y.z, the device driver
does not understand this address.
Therefore, a module (ARP) is provided that will translate the IP address to the
physical address of the destination host. It uses a lookup table (sometimes
referred to as the
physical address of the destination host. It uses a lookup table (sometimes
referred to as the
ARP cache
) to perform this translation.
When the address is not found in the ARP cache, a broadcast is sent out on the
network, with a special format called the
network, with a special format called the
ARP request.
If one of the machines on
the network recognizes its own IP address in the request, it will send an
ARP
reply
back to the requesting host. The reply will contain the physical hardware
address of the host and source route information (if the packet has crossed
bridges on its path). Both this address and the source route information are
stored in the ARP cache of the requesting host. All subsequent datagrams to this
bridges on its path). Both this address and the source route information are
stored in the ARP cache of the requesting host. All subsequent datagrams to this