openstack/openstack-manuals
Code Issues Proposed changes

Description of Network Components

Browse Source 
Brief description of various network components, switches, routers, firewalls and load balancers.

Change-Id: I53551382b2f07581ba9d50c3f187457c24d4aead
Closes-Bug: #1466292
This commit is contained in:
Sangeetha Srikanth 2016-02-18 22:58:51 -06:00
parent 7465d85f17
commit 5834eacfc4
1 changed files with 31 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
doc/networking-guide/source/intro-networking-components.rst
View File

@ -5,27 +5,46 @@ Network components
Switches
~~~~~~~~
A switch is a device that is used to connect devices on a network.
Switches forward packets on to other devices, using packet switching to
pass data along only to devices that need to receive it. Switches operate
at layer 2 of the OSI model.
Switches are devices that enable packets to travel from one node to
another. They are Multi-Input Multi-Output devices. Switches connect
hosts that belong to the same layer-2 network together. Switches enable
forwarding of the packet received on one port (input) to another port
(output) so that they reach the desired destination node. Switches operate
at layer-2 in the networking model. They forward the traffic based on the
destination Ethernet address in the packet header.
Routers
~~~~~~~
A router is a networking device that connects multiple networks
together. Routers are connected to two or more networks. When they
receive data packets, they use a routing table to determine which
networks to pass the information to.
Routers are special devices that enable packets to travel from one
layer-3 network to another. Routers enable communication between two nodes
on different layer-3 networks that are not directly connected to each other.
Routers operate at layer-3 in the networking model. They route the traffic
based on the destination IP address in the packet header.
Firewalls
~~~~~~~~~
A firewall is a network device that controls the incoming and outgoing
network traffic based on an applied rule set.
Firewalls are used to regulate traffic to and from a host or a network.
Firewalls can either be a specialized device connecting two networks or can
be a software-based filtering mechanism implemented on an operating system.
Firewalls are used to restrict traffic to a host based on the rules
defined on the host. They can filter packets based on several criteria such as
source IP address, destination IP address, port numbers, connection state,
and so on. It is primarily used to protect the hosts from unauthorized access
and malicious attacks. Linux-based operating systems implement firewalls
through ``iptables``.
Load balancers
~~~~~~~~~~~~~~
A load balancer is a network device that distributes network or application
traffic across a number of servers.
A load balancer can be a software-based or a hardware-based device that allows
traffic to be evenly distributed across several servers. By distributing the
traffic across multiple servers, it avoids overload of a single server thereby
preventing a single point of failure in the product. This further improves the
performance, network throughput, and response time of the servers.
Load balancers are typically used in a 3-tier architecture. In this model,
a load balancer receives a request from the front-end web server,
which then forwards the request to one of the available back-end database
servers for processing. The response from the database server is passed back to
the web server for further processing.