The Network Layer - Understanding ARP, IP Addressing, Subnet Mask, CIDR, and Routers

This article discusses the network layer, including ARP, IP addressing, subnet mask, CIDR, and routers. Learn how routers move packets forward and how DNS handles name resolution.

Running head: Week 5
The Network Layer
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Author Note

Running head: Week 5
Week 5:
This week discussed about the internet or the network layer. the ARP or the address
resolution protocol is analysed the arp determines the mac address of the device that are on
the local network with a specific IP address. The ARP sends broadcasts to ask questions. If
the asked machine responds then the mac address will be entered in the ARP cache. When the
arp command is successful it enters in to the ARP cache. And that would be the local mac
address and ip address pair. The new entries that are added only added as the results of the
network traffic. The dive which are on the network needed a ip address. Two tpes of ip
address is there one is the IPv4 and another is the IPv6. The ip address enables the device to
be uniquely identified by the ip address of the device. The IPv4 is 32bits long and divided in
to four octates each of the octates has 0-255 decimal numbers. Ip addresses assigned in to the
computers by manually or automatically. To communicate on the network of the IP the
machine requires the ip address, local router address that is called the default gateway and the
subnet mask. The ip adresees are consists of two parts one is the high order bits that specifies
the ip network on the ip addres. And another one is the low bits that specify the unique part of
the ip address. The network bits are the common to all host and the nodes bits are the
particular to the host of the network. The subnet mask is applies to the all machine on the
host networks ip address. The format of the subnet mask is first there is a series of 1bits that
indicated the network portion and there is the second portion that is the node portion
indicated by binary 0 bits. There are two ways of determining the ip address first we can
replace all the node bits with the zeros then we can get the ip addresses network address. And
secondly if we do the bitwise AND of the IP address with the subnet Mask then also we can
get the network address of the ip address. Another way to express the network bits number is
the CIDR that is classless inter domain routing. It is mostly equivalent with the subnet mask.
The main role of the routers are to ove the packets of the network forward another step

Running head: Week 5
toward the destination. The routers move only one packet at a time. When the packets are
arrived in the router the router then determines the packets source and the destination of the
frame and sends the packet to the route. The routers are communicate among themselves one
router is aware of the condition of another router like one router is overloaded, or the router is
offline or the router is removed from the network. There are some routing protocols that are
common like the open shortest path (OSPF), Rputing information protocol (RIP), BGP
(Border gateway protocol). The name resolution of the names of the internet is handled by the
DNS that is domain name system.