Implementing the EIGRP

It is basically defined as (EIGRP)-Enhanced Interior Gateway Routing Protocol.

It an advanced distance vector routing protocol which was developed by the Cisco. Different sort of topologies and the media are suited for the EIGRP. When the network was in a well-designed and works fine, then the EIGRP scales will provides very quick and extreme convergence times in a minimal overhead. And in the Cisco devices EIGRP is a popular choice for routing the protocols.

Introduction of EIGRP:

It combines the distance vector routing protocols and the advantages of link-state. The EIGRP is a hybrid routing protocol or an advance distance vector which are included in the following features.

• Load balancing: unequal metric load balancing was enabled by the EIGRP. Which helps in the traffic flow in the networks to be better for the administrators.
• Easy summarization: summary routes are created anywhere by the administrators which was enabled by the EIGRP and it was enabled within the network. Rather than to depends on the traditional vector distance and performing the class full at major network places of boundaries.
• Classless routing: EIGRP will advertises a routing mask of various destination network because it is a class routing protocol and it enables the EIGRP to support the (VLSM) variable-length subnet masks and various discontinues Subnetworks.
• Reducing the usage of the bandwidth: the periodic updates are not formed in the EIGRP. And to these when there is a change in path or the metric of the route it sends a partial updates. When information the path changes, an update was sent by the DUAL about that certain link not rather than the entire table.
• Less Overhead: rather than using the broadcast, EIGRP uses the multicast and the unicast. And to this effect the stations at the end are unaffected and requests for the topology information.
• Support of multiple network layer: IP version 6(IPv6), IP version 4(IPv4), AppleTalk, and the Novell internetwork packet Exchange (IPX) are mostly supported by the EIGRP, those area also used in the protocol-dependent modules (PDM). And these PDM are responsible for the network layer protocol requirements. 

Rapid Convergence: And to obtain the rapid convergence the (DUAL) Diffusing Update Algorithm are used by the EIGRP. EIGRP stores all the data and makes a backup which was available from the routers which are using it. And if there was no backup or an appropriate router exits in the system or in the local routing table then the EIGRP queries the neighbours to implement another source of alternate route.  

And in the EIGRP the route are described according to their work the best route is known as a successor route and the backup route is called a feasible successor. The following two types of parameters are used in EIGRP in order to determine the best route and the backup route.

• Feasible Distance: The distance between the advertised particular network and from the neighbour plus for to reach the neighbour.
• Advertised Distance: The metric of a EIGRP to their neighbour for to reach a certain required network.

Managing Traffic with Access Control Lists

To classify the IP packets, standard and extended Cisco IOS access control lists (ACLs) are used. And by using ACLs, various features can be applied, mainly as dial on demand routing (DDR), policy-based routing, encryption, quality of service (QoS), Port Address Translation, and the Network Address Translation (NAT), are the packets classified.

Access Control List Operation:

To know how to determine and implement on the Cisco network and systems there should be through understanding on the access control lists (ACL). Filter packets and the security feature on the inbound and the outbound router interfaces will be provided by the access control operation.

 

Understanding the ACLs:

ACLs are primarily used in Cisco devices by two main functions they are filtering and the classification and they are explained as below:

• Filtering:

In the increase router connection around the network the increase of internet all over the globe randomly increases the new sort of challenges are occurred. The network administrators face a various problems and they have a dilemma of how to terminate the unwanted traffic and allow clear access to the appropriate users. And for example data can be filtered from the rest of the network from accessing the important and sensitive data from the finance subnet using the ACL as a filter.

• Classification:

ACLs are used in the router to identify the traffic control. Traffic was identified and classified by the ACL the router can be configured to know and to handle the traffic. And by considering the example the ACL is identified in the certain subnet and the priority is given by the ACL over different types in the congested WAN link.

Using the ACLs in the filtering and the classification they provide a powerful toolset in the Cisco IOS. Various ACLs, administration uses the tools to block the traffic from the internet at which will provide an over controlled access to manage the Cisco IOS devices and which provides the address translation for the private address such as the 192.168.0.0 network.

Cisco have the whole access and it will deny or permit the ACLs following points:

• Ports of the router administration telnet traffic into or out of the router.
• The packets are used to the crossing from the various specified router interfaces and the traffic which was going along the Router.

In the traffic the IP is permitted in and out at all the various interfaces by default.

When the packets are discard by the router then, a packet is reached to the sender notifying the destination was not reached. “Destination unreachable (U.U.U.)”is a discard result shown by ACLs in an IP protocol. And in a trace route “Administratively prohibited (! A *! A)” is sent in a response of the ping.

Differentiate in the traffic can be classified in the IP ACLs. Specially defined traffic in the ACL is enabled and assign to the special handling such as.

• To identify the type of the traffic which has to be encrypted in the Virtual Private Network (VPN) connection.
• The address to be translated are identified by using the Network Address Translation (NAT)
• The traffic across the routed in a designated link is use of policy-based routing to identify the designated link.
• Rotes that are required and distributed form one routing protocol to another can be identified. 
•  During the time of congestion they will schedule in a queue that which packet is required to assign with a quality of service (QoS).

Understanding the WAN Technologies

In today’s growth of the enterprises around the world they were developed to vast area and beyond the single location, at becomes a must to interconnect those using LANs in various locations in order to form the WANs. There are so many technologies around us in forming the WAN connections in both the hardware and software functions.  

 

What Is a WAN?             

It is data communication network which mostly operates and functions beyond the scope of the LAN.

It was used and provided by the service provider or the carrier mostly as cable or a company. The locations of the organization are connected to each other and to the locations of the other organizations, to remote users and the external services. They carries a variant types of signals like voice, video and the data.

The following three aspects shows the major form of characteristics in the WANs:

• To provide the bandwidth to large sort of geographical areas various number of serial connections of various different types are used in the WANs.
• Devices which are separated by wide geographical areas are connected by the WANs
• Various services of carriers mainly as network providers, satellite systems, cable companies and telephone companies are used by the WANs.

To share the data in a home group network in an office of large circuited WAN is mostly used in communicating or sharing the data to the desired person.

WAN Communication Link Options:

Depending on the total number of data transmissions which are required in for the WAN they are accessed in a so many number of ways.

The following diagram shows the WAN connectivity and its options:

In WAN there exists of two major categories in the communication links they are switched and dedicated and with each type of categories single individual types of communication is existed and as follows:

• Circuit- switched communication links: Between the receiver and the sender their established a dedicated sort of virtual connection in for the data or voice by the circuit switching. There need to establish connection throughout the network of the service provider before the actual communication is started.

• Dedicated communication links: when there is a requirement in the permanent dedicated connection, then there was uses the point-to-point lines with various other form of the capacitors and user who are willing to pay for those dedicated lines and the limitations are underlying in the physical facilities. In the point-to-point connection the WAN helps to communicate among the customer and the provider network which are in the remote areas. They are also called as the leased lines because they are actually leased from a carrier.

• Packet Switched Communication Links: Due to fluctuate in the data flow and so many WAN users will not make any sufficient use of the switched, dedicated or in the permanent circuits of the fixes bandwidth. To make the service to the users the communication providers have the networks in the data. The data is transmitted through the packets, frames, or cells in the packet- switched networks.