Denial of service for proxy /sql server

Question

I develop a proxy, which runs queries on sql server.

I.e. the users "talks" to proxy ,and proxy sends the client`s requests to the sql server.

I am wondering how to prevent the proxy to be blocked, if one of its clients sends requests which are not legal. In this case sql server will block the proxy ,since eventually the requests are sent from the proxy`s IP. But other proxy clients will not be able to access the proxy ,since the proxy will be blocked. I want to permit the proxy to work as usual,but rather block only the client who attacked.

Answer 1

There are many ways through the same proxy will be blocked.. I am giving two reasons here..

First, (please specify Version of SQL)

If MS SQL (above 2005) there is a configuration step in server properties, there you can explicitly specify proxy account of SQL Server...(its username and password only) Using the Security mode with SQL Server with Windows Authentication.. The SQL Server will check credentials of the system which is sending request, and then will allow

Second, if there are firewalls(network firewall, not local).. you have to contact your network admin.. He will block all proxy with specified exceptions.

Blocking Individual user(IP) its a network security topic, it is not possible using SQL Server..

But new versions do support that facility also.. will be costly option if you upgrade.. :)

Answer 2

To be honest, I think you should simply ask to close this question as you're premise is wrong to start with.