Specifying a network adapter for SqlConnection

Question

I have 2 network cards in my machine:

Network A auto-assigns the IP address.
Network B is where a SQL Server is present.

When I connect using C#, the connection is intermittent. Can I specify my C# code to use a specific network adapter?

SqlConnection myConnection = new SqlConnection(
                                 "user id=username;"
                               + "password=password;"
                               + "server=serverurl;"
                               + "Trusted_Connection=yes;" 
                               + "database=database;"
                               + "connection timeout=30");

No. Do the two networks share IP scheme? If not, it should just work anyways. If so, you likely have bigger problems. — BradleyDotNET, Mar 03 '15 at 00:03
Would the same IP address appear on both networks? If so, you don't know which adapter to look on (in general, not just for SQL Server) — BradleyDotNET, Mar 03 '15 at 00:15
no - the ip address range is totally different so it's not that. Any other ideas ? — user1438082, Mar 03 '15 at 00:28
Make sure its *not* intermittent if you disable A? Otherwise, no, I don't know where your problem lies. — BradleyDotNET, Mar 03 '15 at 00:45
This can be solved by configuring windows to route the SQL Server default port (1433) to the desired network card. See http://stackoverflow.com/a/11535395/2516770 for the way to set up the routing. — Keith Payne, Mar 03 '15 at 04:47

score 1 · Answer 1 · answered Jan 29 '18 at 07:25

In common scenario, you can't choose a network adapter to manually route outgoing traffic as this can breach your security. Just google for "strong host model" and "weak host model" (it depends on OS version for Windows and distribution origin for Linux).

For example, this is good overview on this matter: https://blogs.technet.microsoft.com/networking/2009/04/24/source-ip-address-selection-on-a-multi-homed-windows-computer

So, after all, you have nothing to do with network card selection. And if your connection is non-stable, you have to troubleshoot the network (router malfunction, throughput overload, firewall inspection delay etc.).

Specifying a network adapter for SqlConnection

1 Answers1