As you people know that you can easily identify systems in your network that are running SQL SERVER INSTANCE but is this possible that I can force DHCP to recognize my application?
example: I have many clients and a single server. but in secure networks out-bond traffic and port listeners are blocked. so I am trying to use reverse model.
I am successful in getting information about all the leased IP through querying DHCP but I want that my clients can query DHCP that where is my server and I want this without having access to DHCP server.
Scenario#1: Server Running on: 192.168.3.245 DHCP: 192.168.3.1 when my client application runs on some machine it query DHCP about the server and DHCP should tell him that your server is running @ 192.168.3.245
Server Started, Begins initialization
Requested IP from DHCP Server [broadcast a packet called DHCP Discover packet] Server replies and assigns an IP
- DHCP Offer Paket [Determines Configuration]
- DHCP REQUEST ... and continues finally get an IP
What I want is to send some Vendor Specific information to DHCP server so that it can store it its filed 43. and When my filed 43 aware [parsing logic present in client]client will turn on it will send a packet by filling field 60 so that DHCP server returns that vendor specific information to my client i.e vendor specific information stored in field 43. I can store N bytes there means I can store my Server IP address and that can be useful for clients.
I hope this is clear now.. if you are interested then kindly read
RFC 2131 STANDARDS TRACK MARCH 1997