Added support for binding the socket to address and port

README.md

@@ -95,6 +95,11 @@ on each `get`, `getAll`, etc.
    between each). A backoff can be implemented by timeouts along the lines of
    `[ 1000, 2000, 4000, 8000 ]`. Retransmissions can be disabled by using only
    a single timeout value: `[ 5000 ]`.
+ - `sourceAddress`: The IP address to bind the socket to, and where requests
+   are coming from. Must be an IP address on the node, if specified.
+   Default is to bind to all interfaces.
+ - `sourcePort`: The UDP port number to bind the socket to, and where requests
+   are coming from.  Default: `0` (random).
 
 ### VarBind objects
 

lib/snmp.js

@@ -485,10 +485,19 @@ function Session(options) {
     // If exclusive is false (default), then cluster workers will use the same underlying handle,
     // allowing connection handling duties to be shared.
     // When exclusive is true, the handle is not shared, and attempted port sharing results in an error.
-    self.socket.bind({
+    var bindOptions = {
         port: 0, //get a random port automatically
         exclusive: true // you should not share the same port, otherwise yours packages will be screwed up between workers
-    });
+    };
+    if (self.options.sourceAddress) {
+        // Support binding to specific source address (wanted on multi-homed nodes)
+        bindOptions.address = self.options.sourceAddress;
+    }
+    if (self.options.sourcePort) {
+        // Support binding to specific source port
+        bindOptions.port = self.options.sourcePort;
+    }
+    self.socket.bind(bindOptions);
 }
 
 // We inherit from EventEmitter so that we can emit error events