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Commands used in Dockefile - Part4

  Docker is an opensource tool used for virtualization and deliver software in the form of packages called Containers. It is one of the most important tools used in networking domain.  Dockerfile  is a template for building the image which contains commands needed to package the software. In this post, I am going to explain the commands ADD & COPY used in  Dockerfile .   ADD Command:   ADD command is used to copy files, directories or files from remote URLS to destination path in the image. The source paths can contain wildcards.   If the destination has relative path, it is relative to the Working directory of the image. Note that source path is always relative to the Docker build context.   ADD command will not support authentication. So, if there are any protected files to be added in  Dockerfile  building, use other tools like curl or  wget   Dockerfile  copying Single & Multiple files, directory using ADD inst...

Modern Day Networking Terminology

In this post, we will look at some of the terminologies used in modern-day networking. Some of the terms of modern networking are as below:

IP Backbone / Core Network:
It’s nothing but just a portion of internet or enterprise network consisting of high-performance routers. Also, it has high volume optical links that use Wavelength Division Multiplexing. By 2020, the speed of the core router per optical link will be 400Gbps - 1Tbps.

Edge Routers / Aggregation Routers:
These are the routers used in the enterprise and helps in connecting with the high-speed WAN network or core network. By 2020, the speed of aggregate router per optical link will be 200-400 Gbps.

Connections in Enterprise Network:
In general, Enterprise network main campus and its branches are connected via Ethernet or Multiprotocol Label Switching technology. Critical assets are protected from the internet or IP backbone by using the firewall concept.

Connections of IP Backbone:
Generally small and medium-sized businesses are connected to the enterprise network via IP Backbone through Ethernet LAN. Residential users are connected to the internet using cable modem or wireless connection. Mobiles and Tablets are connected using some public cellular network.

The above diagram shows an overview of the global network ecosystem. Now we will see a typical enterprise network ecosystem that has three-tier designs. The tiers are as below:
  • Access Network
  • Distribution Network
  • Core Network
Access Network: 
It is the network closest to end-user and is mostly LAN based. It supports end-user equipment like mobiles, PCs and some local server serving users of Local access network. The routers of this layer are connected to the distribution network through the internet, public or private connections. Hence, the routers in this layer function as the edge router that forwards traffic to and from the access network.

Distribution Network:
This network helps in maintaining the connection between the access networks as well as connecting with the core network. An edge router in the distribution network is connected to the edge router in the access network for maintaining connectivity. It also serves to aggregate traffic reaching the core network to protect the core network. Also, it may have connectivity with database and network management servers used by access networks. Note that all routers in this network are not edge routers and are for internal purpose in the enterprise.

Core Network:
This helps in connecting distribution networks in geographical locations and providing access to other networks which are not part of the enterprise. It has high-performance routers, high capacity transmission lines. Some routers in the network are purely used for redundancy purpose.

 
The above diagram shows the level of hierarchy in the typical Enterprise Network.

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