Question : Local Area Connection and LoopBAck

I have seen some servers [they have web application inside], and they have 2 network adapters: one is Local Area Connection and  one is LoopBAck , the loopback tcp/ip configuration has only the IP address and subnet mask which is entered, the rest is all blank, the  Local Area Connection adapter tcp/ip has all the settings.  The server is in the DMZ.

I would like to know in this scenario what is the usage of loopback.

thanks

Answer : Local Area Connection and LoopBAck

Lilshooter is right. I'll provide somemore details for you.

A network connection between a client application and a database server on the same computer is called a local-loopback connection. There's 101 reasons why applications need loopback adapter, and it depends on why the Application needs it.  For Speed? Stability? etc. The networking facilities used are the same as if the client application and the database server were on different computers. You can make a local-loopback connection provided your computer is equipped to process network transactions.

In a local-loopback connection, data appears to pass from the client application, out to the network, and then back in again to the database server. In fact, although the database server uses the network programming interface (TLI or sockets), the internal connection processes send the information directly between the client and the database server and do not put the information out on the network.

In Virtualization, some Virtual Machines run on NAT and require loopback to be used to circulate packets around it's own network.

In your scenario, i realise you mentioned DMZ. seems like you're running a Server upholding certain services. Let me assume it is MSSQL. Say you're actually managing the MSSQL server on the server itself, assume you use Enterprise Manager to manage it, during connection, you place in your server's (ip/hostname) which is actually the same server you're connecting to; this is actually a loopback connection. So that all data are parsed on the same server without going around the network again.

Let us know how we can help,
John