Recent Posts

Pages: [1] 2 3 ... 10
Career and Professional Development / Anonymous Personals Chat
« Last post by Josephrida on October 16, 2017, 04:17:33 PM »
Useful Software Free / Exam Creation Softwares
« Last post by certforumz on October 12, 2017, 08:33:23 AM »
Useful Software Free / Screen Capture Software for Youtube Movies
« Last post by certforumz on October 12, 2017, 08:25:07 AM »
Checkout the following review of free screen capture software that is useful in making youtube movies:
Author recommended

Also checkout the free (trial or limited) video editing software for youtube:
1. Windows Movie Maker from Microsoft
2. Filmora Video Editor
3. Lightworks and other

CCNA Certification / Re: CCNA Links
« Last post by certforumz on October 11, 2017, 06:58:49 AM »
Excellent write up on OSPFv2 and OSPFv3 comparison:

Differences in  OSPFv3 from OSPFv2

Most of the algorithms have been preserved from OSPFv2, however, some changes were needed either to support larger address space or due to changes in protocol semantics between IPv4 and IPv6.

Following are the differences between OSPFv3 and OSPFv2-

1. Protocol processing per-link, not per-subnet:

IPv6 uses the term "link" instead of "subnet" or "network" to define a medium used to communicate between nodes at the link layer. Multiple IP subnets can be assigned to a single link, and two nodes can communicate with each other even if they do not share a common IP subnet.

This change affects Hello packets and Network LSAs processing.

2. Removal of addressing semantics:

    IPv6 addresses are not present in OSPF packets, except in Link-State Update (LSU) packets.
    Router and Network LSAs do not contain network addresses, but only contains topology information.
    OSPF Router ID, Area ID and Link-State IDs remain at 32-bits size- they cannot be assigned IPv6 addresses.
    Neighboring routers are identified by Router IDs only.

3. Addition of Flooding scope:

There are three seperate scopes for flooding LSAs-
    Link-local scope- LSA is flooded only on local link and no further. New Link-LSA uses link-local scope.

    Area scope- LSA is flooded in a single OSPF area. Router-LSAs, Network-LSA, Inter-area Prefix-LSAs, Inter-area Router-LSAs and Intra-area Prefix-LSAs use Area scope.

    AS scope- LSA is flooded throughout the routing domain. AS-external LSAs use AS scope.

4. Explicit support for multiple instances per link:

Providers may run different OSPF domains and would like to keep it seperate even though if they have one or more links in common, can use multiple instances on the same link.

If someone wants a single link in more than one area can use multiple instances on the same link.

Multiple instances on the single link can be achieved using "Instance ID" contained in the OSPF packet header.

5. Use of Link-local addresses:

OSPFv3 requires that every interface has a link-local address from the range FE80/10. A router uses the link-local address as next-hop during packet forwarding for the neighbors attached to its links.

On virtual-links, global or site-local addresses are used for packet forwarding.

Link-local addresses are only sent in Link-LSAs, and not allowed in any other OSPF LSAs.

6. Authentication changes:

In OSPFv3, Authentication for OSPF has been removed. OSPFv3 relies on IPv6 Authentication Header (AH) and Encapsulating Security Payload (ESP) to ensure integrity and authentication/confidentiality of routing exchanges.

Accidental data corruption is handled by checksum.

7. Packet Format changes:

    Version number is now 3.
    No Authentication fields.
    Options field Hello and DBD packets is now 24-bits long
    Two option bits, "R" bit and "v6" bit, are added to Options field for processing Router-LSAs during SPF calculation.
    "Instance ID" is included in Hello packet

8. LSA Format changes:

    Options field is removed from LSA header, increased to 24-bit and moved to Router-LSAs, Network-LSAs, Inter-area Router-LSAs (Type-4 LSA in OSPFv2) and Link-LSAs.
    LSA Type field is expanded to 16 bits with upper 3 bits encoding flooding and handling of unknown LSA Types.
    Addresses in LSAs are now expressed as [prefix, prefix-length]. The default route is expressed as a prefix with length 0.
    Router and Network LSAs have no address information.
    Router LSAs are concatenated before SPF is run.
    New Link-LSA is introduced. They have link-local flooding scope. They have 3 purposes- a) they provide router's link-local address to all neighbors attached to that link b) inform other routers on the link of IPv6 prefixes to associate with the link c) they allow the router to assert a collection of Option bits to associate with the Network LSAs that will be originated for the link
    Type-3 summary LSA is now Inter-area Prefix-LSA and Type-4 summary LSA is now Inter-area Router-LSA.
    New Intra-area Prefix-LSA is introduced. It carries all IPv6 prefix information that in IPv4 is carried in Router and Network LSAs.

9. Handling Unknown LSA Types:

Unknown LSA Types are either treated as having link-local flooding scope, or stored and flooded as if they were understood.

10. Stub Area support:

Stub area support has been retained in OSPFv3. Only Router-LSAs, Network-LSAs, Inter-area Prefix-LSAs, Intra-area Prefix-LSAs and Link-LSAs are allowed in a Stub area.

Unknown LSAs are labelled as "Store and Flood LSAs" as if type understood under following conditions-

a) the LSA has area or link-local flooding scope
b) the LSA has U-bit set to 0.

11. Identifying neighbors by Router ID:

Neighboring routers on a given link are always identified by a Router ID. This behaviour is valid for neighbors on point-to-point, virtual-links, broadcast, NBMA and point-to-multipoint links.

Router ID is reserved.

Further reading:

1. RFC 2740: OSPF for IPv6
CCNA Certification / What is New in CCNA v3?
« Last post by certforumz on October 11, 2017, 05:03:50 AM »
The CCNA Routing and Switching (v3.0) certification offers more job role-focused training as compared to previous versions; now network engineers will gain meaningful and updated networking knowledge with advance skills to configure, manage and troubleshoot LAN and WAN in a routing/switching domain.

Some newly-added technologies include:

    EIGRP implementation for IPv6 networks
    Multi-area OSPF (both OSPFv2 and OSPFv3)
    Introduction to IPv6 Access Control Lists (ACLs)
    Configuration and verification of PPP Multilink and LLDP (Link Layer Discover Protocol)
    Introduction to basic Cloud services and resources
    Basic IP SLA implementation to troubleshoot connectivity (icmp-echo) and introduction to SPAN

Along with the above-listed technologies, Cisco has also introduced some highly advanced technologies to the CCNA R&S v3.0 (I am very much surprised and grateful to Cisco for introducing advanced technologies such as BGP, QoS and VPN in an entry-level certification program). Now, CCNA R&S v3.0 candidates will also be able to get an introduction to the following advanced technologies:

    Introduction to VPN technologies such as site-to-site VPN, Dynamic Multipoint VPN (DMVPN), and client VPN
    Basic implementation of BGP peering and route advertisement
    Introduction to Quality of Service (QoS) concepts.

Cisco not only added new technologies to CCNA R&S v3.0, they have also said goodbye to some technologies. For now, technologies like VRRP, GLBP, Troubleshooting Frame Relay and layer 1 issues, etc. will not be a part of CCNA R&S, so if you are starting the preparation for CCNA R&S v3.0, you can skip the above listed technologies.

Growing Lemon Plantation / Lemon News - Delhi Faces Shortage of Lemons in Summer
« Last post by certforumz on September 28, 2017, 04:36:52 AM »
 New Delhi, March 30: 

Lemon prices have soared to Rs. 100 a kg in the national capital’s retail market due to supply crunch, which spells bad news ahead of the gruelling summer.

Used primarily for its juice in culinary and non-culinary applications, lemon prices have doubled to Rs. 80-100 a kg in the retail market over the past one week, traders said.

They attributed the jump in cost to an over 25 per cent drop in supply from the major producing state of Andhra Pradesh.

Against the normal arrival of 15-20 trucks of lemons (each carrying about 15 tonnes), only 10 trucks are currently coming to the Azadpur market (Asia’s biggest fruits and vegetables market), the Lemon Traders’ Association President, Mr Tilak Rajm, told PTI.

The citric produce, having tremendous medicinal potential, is selling in the Azadpur wholesale market at Rs. 40-60 per kg, he said.

The Lemon Association’s General Secretary, Mr Shyam Sundar Vohra, said excessive rains in Andhra Pradesh in the past three months have damaged almost 50 per cent of the crop there.

Tamil Nadu, Gujarat, Karnataka, Orissa, Maharashtra, Assam and Rajasthan are the other leading producers of the crop.

India is the leading producer of lemon in the world, accounting for about 16 per cent of international production. It is followed by Mexico, Argentina, Brazil and Spain.

Products / Computer Based Test CBT Engine for Authors, Educators, Training Institutes.
« Last post by certforumz on September 27, 2017, 10:56:19 AM »
Computer Based Test CBT is an pff line exam creator software that allows you to build quizzes, tests and assessments, both online and on paper. Creating and managing an exam has never been easier: CBT makes a time-consuming chore a whole lot easier and the result considerably more professional.

You can use CBT as an assessment software to build your exams with several features, for example multiple question types, randomization, security options, question sharing, professional layouts, custom certificate generation, tablet support, and much more. CBT exam software the ideal assessment tool to make and manage your exams.

CBT exam engine together with author module is used by educators, trainers, non-profits, businesses and other professionals who need an easy way to make exams, tests, and quizzes online quickly: you can create and publish your first exam in a few minutes! Questions can be manually added using the built-in editor (with support for math equations too) or imported from external files.

As a professional exam creator, CBT can help teachers with both formative and summative assessments, also serving as meaningful sources of information, helping you identify what you taught well and what you need to work on. As an employee training tool, instructors and trainers can can carry out assessments in various ways to help ensure that learning requirements and objectives are being met on a continuous basis.

Download here:
Pages: [1] 2 3 ... 10