TCP Protocol: TCP 3-way handshaking #2

tcp-protocol

In the last post, we have explained the TCP 3-way handshaking from an abstract point of view, and knew that one of the main functions of this handshaking is to exchange and synchronize some parameters for the TCP connection endpoints to facilitate its job. We also knew that two of the main parameters that the end-points exchange in the TCP 3-way handshaking are the SEQUENCE and ACK numbers. Today, we will continue the 3-way handshaking process in more details. Above is a TCP capture file which I downloaded from “Wireshark” wiki page that shows 3 packets in sequence between two end-hosts. From …

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TCP Protocol: Three-way Handshake

tcp-protocol

We all know by now that the basic function of the TCP protocol is to send a stream of bytes that has no shape or fixed size over a network reliably to a receiver. We all also know that reliable delivery involves building a connection between two end-hosts, and this will be the first step that the TCP stack do to exchange data. Above figure, has a host on a side and a server on the other. Host needs to get/download a file from the server via FTP protocol which is dependent on TCP. The Host will start off by allocating …

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TCP Protocol: The Overview – Part1

tcp-protocol

One of the most important layers we – as network engineers – hate and avoid in the OSI reference model is the transport layer with its popular and dominant protocol; TCP. Most of network engineers abandoned diving into TCP protocol because they consider it a host-to-host communication protocol that usually works without a problem. End systems either Windows or Linux gets installed with their own version of TCP stack with some pre-configured values that usually don’t break, so why would we bother ourselves learning about one of the most important protocol in the TCP/IP stack! The irony here is that, System Engineers, Application …

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JUNOS Disable vs Deactivate interfaces

NETspresso

Confusing between disabling and deactivating interfaces on JUNOS is a common mistake that leads to all sorts of problems during implementing changes on live network boxes. Let’s look and clarify the differences quickly. Disabling an interface: Disabling an interface in JUNOS is equivlaent to interface shutdown in Cisco, it is going to take the interface administratevly down completely without impacting the configuration on that interface as you can see below. --- Interface in UP UP state triton@neptune> show interfaces ge-0/0/0 terse Interface               Admin Link Proto    Local                 Remote ge-0/0/0                up    up ge-0/0/0.0              up    up   inet     172.18.0.1/24 -- Disable the interface triton@neptune> …

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SDN is an Iteration that will Lead Innovations

Good_Read

I have stumbled upon a recent post from Greg Ferro on Ethrealmind, the post is titled SDN is not an innovation, it’s an iteration. I actually wanted to share this post because it kind of puts things into prespective. The word innovate refers to creating something that is new and disruptive. Innovations needs to come with a whole new paradigm for doing the things we are doing. At one time it was easier to apply the term to the work of Newton, Einstein or  Nicola Tesla. These days, it’s  much harder to apply the term to things, that are just …

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Software-Defined Networks .. A Primer

SDN,_Ethernet_y_NFV

SDN, Software-Defined Networking, the trending technology that some friends/colleagues of mine like to refer to it as “Still Does Nothing”. Let’s see if it does some thing. SDN has been a market hype for few years now.  Out of laziness, I ignored it in the beginning then I had to catch up a bit later and learn what was exactly going on.  From who I know many engineers have taken the same path and are still ignoring SDN, probably out of the feeling that we have enough to learn something new. Lately, SDN has been reduced to a buzzword that …

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