List of Server Variables In ASP.NET

Variable	Description
ALL_HTTP	All HTTP headers sent by the client.
ALL_RAW	Retrieves all headers in raw form. The difference between ALL_RAW and ALL_HTTP is that ALL_HTTP places an HTTP_ prefix before the header name and the header name is always capitalized. In ALL_RAW the header name and values appear as they are sent by the client.
APPL_MD_PATH	Retrieves the metabase path for the Application for the ISAPI DLL.
APPL_PHYSICAL_PATH	Retrieves the physical path corresponding to the metabase path. IIS converts the APPL_MD_PATH to the physical (directory) path to return this value.
AUTH_PASSWORD	The value entered in the client's authentication dialog. This variable is available only if Basic authentication is used.
AUTH_TYPE	The authentication method that the server uses to validate users when they attempt to access a protected script.
AUTH_USER	The name of the user as it is derived from the authorization header sent by the client, before the user name is mapped to a Windows account. This variable is no different from REMOTE_USER. If you have an authentication filter installed on your Web server that maps incoming users to accounts, use LOGON_USER to view the mapped user name.
CERT_COOKIE	Unique ID for client certificate, returned as a string. Can be used as a signature for the whole client certificate.
CERT_FLAGS	bit0 is set to 1 if the client certificate is present. bit1 is set to 1 if the cCertification authority of the client certificate is invalid (it is not in the list of recognized CAs on the server).
CERT_ISSUER	Issuer field of the client certificate (O=MS, OU=IAS, CN=user name, C=USA).
CERT_KEYSIZE	Number of bits in Secure Sockets Layer connection key size. For example, 128.
CERT_SECRETKEYSIZE	Number of bits in server certificate private key. For example, 1024.
CERT_SERIALNUMBER	Serial number field of the client certificate.
CERT_SERVER_ISSUER	Issuer field of the server certificate.
CERT_SERVER_SUBJECT	Subject field of the server certificate.
CERT_SUBJECT	Subject field of the client certificate.
CONTENT_LENGTH	The length of the content as given by the client.
CONTENT_TYPE	The data type of the content. Used with queries that have attached information, such as the HTTP queries GET, POST, and PUT.
GATEWAY_INTERFACE	The revision of the CGI specification used by the server. The format is CGI/revision.
HTTP_<HeaderName>	The value stored in the header HeaderName. Any header other than those listed in this table must be prefixed by HTTP_ in order for the ServerVariables collection to retrieve its value. Note The server interprets any underscore (_) characters in HeaderName as dashes in the actual header. For example if you specify HTTP_MY_HEADER, the server searches for a header sent as MY-HEADER.
HTTP_ACCEPT	Returns the value of the Accept header.
HTTP_ACCEPT_LANGUAGE	Returns a string describing the language to use for displaying content.
HTTP_COOKIE	Returns the cookie string that was included with the request.
HTTP_HOST	Returns the name of the Web server. This may or may not be the same as SERVER_NAME depending on type of name resolution you are using on your Web server (IP address, host header).
HTTP_REFERER	Returns a string that contains the URL of the page that referred the request to the current page using an HTML tag. Note that the URL is the one that the user typed into the browser address bar, which may not include the name of a default document. If the page is redirected, HTTP_REFERER is empty. HTTP_REFERER is not a mandatory member of the HTTP specification.
HTTP_USER_AGENT	Returns a string describing the browser that sent the request.
HTTPS	Returns ON if the request came in through secure channel (SSL) or it returns OFF if the request is for a non-secure channel.
HTTPS_KEYSIZE	Number of bits in Secure Sockets Layer connection key size. For example, 128.
HTTPS_SECRETKEYSIZE	Number of bits in server certificate private key. For example, 1024.
HTTPS_SERVER_ISSUER	Issuer field of the server certificate.
HTTPS_SERVER_SUBJECT	Subject field of the server certificate.
INSTANCE_ID	The ID for the IIS instance in textual format. If the instance ID is 1, it appears as a string. You can use this variable to retrieve the ID of the Web-server instance (in the metabase) to which the request belongs.
INSTANCE_META_PATH	The metabase path for the instance of IIS that responds to the request.
LOCAL_ADDR	Returns the Server Address on which the request came in. This is important on multi-homed computers where there can be multiple IP addresses bound to the computer and you want to find out which address the request used.
LOGON_USER	The Windows account that the user is impersonating while connected to your Web server. Use REMOTE_USER or AUTH_US<CODE>ER to view the raw user name that is contained in the request header. The only time LOGON_USER holds a different value than these other variables is if you have an authentication filter installed.
PATH_INFO	Extra path information as given by the client. You can access scripts by using their virtual path and the PATH_INFO server variable. If this information comes from a URL, it is decoded by the server before it is passed to the CGI script.
PATH_TRANSLATED	A translated version of PATH_INFO that takes the path and performs any necessary virtual-to-physical mapping.
QUERY_STRING	Query information stored in the string following the question mark (?) in the HTTP request.
REMOTE_ADDR	The IP address of the remote host making the request.
REMOTE_HOST	The name of the host making the request. If the server does not have this information, it will set REMOTE_ADDR and leave this empty.
REMOTE_USER	The name of the user as it is derived from the authorization header sent by the client, before the user name is mapped to a Windows account. If you have an authentication filter installed on your Web server that maps incoming users to accounts, use LOGON_USER to view the mapped user name.
REQUEST_METHOD	The method used to make the request. For HTTP, this is GET, HEAD, POST, and so on.
SCRIPT_NAME	A virtual path to the script being executed. This is used for self-referencing URLs.
SERVER_NAME	The server's host name, DNS alias, or IP address as it would appear in self-referencing URLs.
SERVER_PORT	The port number to which the request was sent.
SERVER_PORT_SECURE	A string that contains either 0 or 1. If the request is being handled on the secure port, then this will be 1. Otherwise, it will be 0.
SERVER_PROTOCOL	The name and revision of the request information protocol. The format is protocol/revision.
SERVER_SOFTWARE	The name and version of the server software that answers the request and runs the gateway. The format is name/version.
URL	Gives the base portion of the URL.