Our Unixadmin, John from xyz company,  recently upgraded one of his server’s network interface card  from the old one with 100MB speed to a new one with 10Gig speed , and the reason is to improve the speed for the backup of the server. After the NIC Upgrade  john found that the server network performance was improved a little, but still the server is not able to utilize all the available network bandwidth. 

After a bit of investigation john realised that his server TCP window size has to be tuned  to utilize maximum network bandwidth available to the server.  In this post we will be discussing the procedure about “how john tuned the TCP window size  to increase his server network performance?”.

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Let us assume that our system administrator Jack is supporting for a server environment in which a small set of servers  are located in DMZ (Demilitarized zone ) network . In order to connect any DMZ server Jack has to ssh from his machine (windows PC/Unix workstation) to another server which acts as gateway between internal network and  DMZ network, and then he has to SSH to the DMZ server that he want to connect.

 Just to make his life easy to support these DMZ servers for his day-to-day system administration tasks, Jack wants to create a special encrypted tunnel from Jack’s host to the DMZ server.  He wants to achieve this goal by using the secured internal server (i.e. server1) as tunnel server between his PC/workstation and DMZ server.

 Jack’s Network Setup for SSH tunnel:

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Virtual LANs or VLANs are virtual separations within a switch that provide distinct logical LANs that each behave if there were configured on a separate physical switch. Some Important points about VLANS.

•  All the servers connected with in a VLAN will have same broadcasting domain, and can connect to each other directly
•  Servers belongs to different VLANs has to communicate with each other using external Routing device.  
•  To Expand the VLAN across multiple physical switches, physical switches needs to be interconnected using links called Trunks

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IF your organization looking for a solution to host it’s entire application environment in an external vendor’s data center, your organization must  be considering lot many factors to define the standards of the data center. Below post describes some of the Network Connectivity standards used for development, implementation and management of a Data Center managed by a vendor.

This post  assumes that you should have an understanding of the concepts and terminology associated with data communications networks, protocols, and equipment used in this Schedule.

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