Configuration Tips

First Hop Redundancy Protocols (a.k.a. FHRP) are used to allow gateway redundancy. In this article, we cover the basics of this technology, with practical examples of configurations. I’m amazed at how the approach of the CCNA certification has changed since the time I took my test and entered the Cisco world …

Companies seek out VoIP because it enables productivity. Telecom assets were once defined by barriers – the kind that encumbered countless enterprise professionals. Even when, say, the phone and email needed to be used at the same time, these functions were siloed on separate hardware. Transcribing a voicemail to text …

Cisco CCNA Training:  IP Addressing Part 1 Here’s a great video to help you get a better understanding of ip addressing.

  Before I explain what and how explicit tracking of group membership works in IGMP, let me give you a brief introduction to IGMP. A brief introduction to IGMP: Internet Group Management Protocol ( IGMP ) is used by end hosts and routers to exchange multicast group membership information. IGMP …

Protocol Independent Multicast (PIM) – Sparse mode (PIM-SM) is a multicast routing protocol. PIM-SM is used when receivers are sparsely populated. PIM-SM uses explicit-join mechanism. PIM-SM can work on point-to-point link and ethernet LANs.   Why PIM Assert mechanism is required: We will use the network configuration shown in figure-1 …

For anyone who has ever needed to test a new network architecture, implement a new routing protocol or simply study for a Cisco exam has needed access to a real live router or a router simulator.  But buying a bunch of routers just test up an idea or for study …

When configuring high availability gateways between multiple routers you only have a couple of options to choose from. If you have all Cisco routers chances are you will be configuring and using HSRP to provide redundancy between your routers. If you have Juniper, Foundry (Brocade), or any another router you’ll …

Have you heard someone using a phrase ‘Can you ping me at 8:00 PM’ or ‘Please ping me when you are free’? I am sure you must have heard people using such phrases in their daily talks. I think its fairly obvious that they want the other person to check …

Applications/Servers use IP multicast to send their contents in IP packets to a group of interested clients. These clients indicate their wish to receive such traffic explicitly by sending an IGMP (Internet Group Management Protocol) join message. In early years of IP multicast deployment, receivers and senders did not know …

TTL (Time-To-Live) is a field in the IPv4 header. TTL field is of 8 bits and so it can take a maximum value of 255. When a sender sends out a packet, it sets the TTL value (usually as 64) in the IP header. Each router that receives this packet, …