How do I specify the outgoing IP address of a database connection?

I have a web server with multiple IP addresses that needs to connect to a database server. The DB server is behind a firewall that's controlled by an IP address whitelist. (If it matters, it's an Oracle server.) Is there a way to specify the IP address used by the web server in the OracleConnection, so that only one IP needs to be add开发者_JAVA技巧ed to the whitelist?

I see there are a few similar questions about specifying outgoing IP addresses (such as this one and a couple linked from there), but none that specifically mention database connections.

The database side doesn't come into play (much).

On my simple network, I have a modem/router that gets an internet IP address from my ISP and has a different IP address for the local network. I have configured it to forward requests made on port 80 (the port used for HTTP requests) to a particular IP address on my local network.

IP addresses can by allocated dynamically (DHCP) or statically. Because I want my HTTP requests to go to a particular machine, I need that machine to always have the same IP address. One way to do that is have the machine request a static IP address when it connects to the network. Another is to have the router dynamically allocate an IP address but to always use a specific one for a specific MAC address. I've gone the latter route. Which you choose to do and how you do it depend on your situation (eg OS and network setup).

In your situation you want the local network addresses to be static for both the database server and the web server. That's really a networking issue.

The only time that programming may come into play is if you have multiple network ports. Take my laptop. It has a WiFi card and an Ethernet port. Each of those has a unique MAC address (actually every network device in the world has a unique MAC address). I can connect either or both of those ports to a single network or to two different networks.

If I connect both devices to the same network, they must have different IP addresses because an IP address needs to be unique to a network so the network knows where to send the messages. If I connect them to two different networks, then they might get the same IP address. [The Internet is one big network, but local area networks (LANs) are independent.]

If your machine has multiple network connections, you may need to direct a particular connection to a certain network (so I might always want my db connections to use the eth0 port and other things to use and eth1 port).

Generally speaking for a web server, you have one or more externally addressable IPs, but only one internal one.

The internal address is what is connected to your internal network for communicating with things like database servers. The external ones are used when outside clients connect or for outbound communications..

I would assume that the "multiple IP addresses" are in the DMZ (external network) , and that the database server is in a different (internal) network, no? You should not have this problem.