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Cisco Systems and CCNA and Article
Routing Protocols: Article from uCertify
uCertify has sent us this article which is useful for the CCNA (Cisco Certified Network Associate) certification exam. The article helps you to understand the Routing Protocols, which determine the best path to deliver packets by knowing about all other routers connected to the network, a topic for 640-802 exam.
There are two categories of routing protocols, namely Interior Gateway Protocol (IGP) and Exterior Gateway Protocol (EGP).
An Interior Gateway Protocol (IGP) refers to a routing protocol that exchanges routing information between gateways within a single autonomous system. The routing information is used by the Internet Protocol (IP) or other network protocols to specify how to route transmissions. Following are the Interior Gateway Protocols (IGPs):
- IS-IS
- OSPF
- IGRP
- EIGRP
- RIP (RIPv1 and RIPv2)
Intermediate System-to-Intermediate System (IS-IS) is a link-state routing protocol standardized by the ISO. It supports variable length subnet masks (VLSM), uses multicast to discover neighboring routers using hello packets, and supports authentication of routing updates.
Open Shortest Path First (OSPF) is a routing protocol that is used in large networks. Internet Engineering Task Force (IETF) designates OSPF as one of the Interior Gateway Protocols. A host uses OSPF to obtain a change in the routing table and to immediately multicast updated information to all the other hosts in the network.
Interior Gateway Routing Protocol (IGRP) is a Cisco proprietary distance vector Interior Gateway Protocol (IGP). It used by Cisco routers to exchange routing data within an autonomous system (AS). This is a classful routing protocol and does not support variable length subnet masks (VLSM). IGRP supports multiple metrics for each route, including bandwidth, delay, load, MTU, and reliability.
EIGRP is a Cisco proprietary protocol. It is an enhanced version on IGRP. It has faster convergence due to use of triggered update and saving neighbor’s routing table locally. It supports VLSM and routing summarization. As EIGRP is a distance vector protocol, it automatically summarizes routes across Class A, B and C networks. It also supports multicast and incremental updates and provides routing for three routed protocols i.e. IP, IPX, and AppleTalk.
RIPv1 was designed to fulfill dynamic routing needs of a network. It uses MAC-level broadcasts, which are not desirable in the current scenario because all nodes must process all broadcasts. It does not support VLSM and route summarization.
RIPv2 is a classless protocol. It improves upon RIPv1 with the ability to use VLSM and route summarization. It supports route authentication and multicasting of route updates. It is used in small to medium size networks. RIPv2 uses triggered updates to speed up convergence. It supports variable length subnet masks (VLSM).
Variable Length Subnet Masks (VLSMs) allow administrators to divide a given IP address space into more than one subnet. It helps in efficient use of IP addressing. A classless routing protocol is required to deploy VLSM. Classful protocols such as RIP v1 do not support VLSM.
An Autonomous system (AS) is a group of networks under a single administration and with single routing policies. Each AS is assigned a unique number in order to differentiate it from other autonomous systems. The assigned unique number can be from 1 to 65,535. The Internet Assigned Numbers Authority (IANA) is responsible for assigning these numbers. There are public and private AS numbers like private and public IP addresses.
Administrative distance defines the reliability of a routing protocol. The router uses administrative distance in order to choose the best path when there are two or more different routes on a router to the same destination using different routing protocols. Each routing protocol’s administrative distance value decides which routing protocol is more reliable. The lower the administrative distance value, the more reliable the routing protocol.
| Protocol | Administrative distance value |
| IGRP | 100 |
| OSPF | 110 |
| IS-IS | 115 |
| RIP | 120 |
Note: The administrative distance value for static route is 0.
Exterior Gateway Protocol (EGP) is a protocol that exchanges routing information between different autonomous systems. It is commonly used between hosts on the Internet to exchange routing table information. Border Gateway Protocol (BGP) is the only active EGP.
BGP stands for Border Gateway Protocol. It is an interautonomous system routing protocol and is a form of Exterior Gateway Protocol (EGP). This protocol is defined in RFC-1267 and RFC-1268. It is used for exchanging network reachability information with other BGP systems. This information includes a complete list of intermediate autonomous systems that the network traffic has to cover in order to reach a particular network. This information is used for figuring out loop-free interdomain routing between autonomous systems. BGP-4 is the latest version of BGP.
Vendor news and Cisco Systems
Cisco Now Requires Digital Photos and Signatures of candidates
Cisco Systems has recently introduced its new policy in which all candidates must bring their digital photo and provide a digital signature at the test center before taking any Cisco exam. This new policy will be implemented worldwide within a year at Pearson Vue, Cisco’s exclusive test delivery service provider.
According to the company’s Website, a new level of identity authentication will help individuals to establish the authenticity of their certification records in the market place. It is basically seen that some candidates take the exams on behalf of others and also retake the exams to memorize the questions to give to other candidates.
In order to avoid such illegal activities, this policy will be helpful for the examination authorities to get the right verification of the candidates. The new policy will make it easier for the candidates to be identified. The process is also helpful to protect the integrity of Cisco certification and prevent exam fraud. This is one of the many steps that are being taken to maintain test security.
To know more about this official announcement, visit Cisco.com.
Microsoft and Study guide and 70-528 and MCTS .NET
Free Study Guide for MCTS Exam 70-528
En.csharp-online.net is providing a free online study guide for MCTS .NET Framework 2.0 - Web-Based Client Development Exam 70-528. This certification exam validates your skills in designing and implementing Web-based applications with Web forms, ASP.NET, and the .NET Framework.
For obtaining this certification, candidates should have at least one year experience in developing Web-based applications by using the Microsoft .NET Framework. The study guide for exam 70-528 covers all the topics, such as Creating and Programming a Web Application, Integrating Data in a Web Application by Using ADO.NET, XML, and Data-Bound Controls, Tracing, Configuring, and Deploying Applications, etc.
To view this study guide, visit exam 70-528 page.
Study notes and Cisco Systems and CCNA
Free CCNA Study Notes from CertExams.com
Free study notes for the Cisco Certified Network Associate (CCNA) 2.0 exam 640-801 are available at the CertExams Web site. The study notes help you to focus on the core concept. They also provide you an understanding of the technical terms, so that you can prepare well for the actual CCNA certification exam.
This is an entry-level exam that is essential for all other Cisco certifications such as CCNP (Cisco Certified Network Professional) and CCDP (Cisco Certified Design Professional). It is a prerequisite for each of these certifications. To obtain the Cisco Certified Network Associate (CCNA) certification, you must have knowledge of configuring and operating simple routed WAN and switched LAN networks using Cisco products.
The study notes for CCNA provided at the Web site are briefly explained covering all the objectives of this exam.
Novell and 050-632 and Study guide and CNE
Free Study Notes for Exam CNE 050-632 at ExamNotes
ExamNotes.net is offering free study notes for Novell Networking Technologies CNE Exam 050-632. They are available in printable and PDF format. The Networking Technologies exam is one of the core requirements for the CNE certification.
This exam covers a wide range of sub-topics, which are essential for professionals who are working as network engineers, administrators, etc. The study notes for the exam 050-632 provide you the necessary concepts required to prepare for this certification exam.
Note: Free registration is required.