DNS connector
The DNS connector allows you to intercept and potentially modify all requests and responses for the Domain Name Service.
The best way to see this connector in action is to go through the DNS tutorial.
Parameters
This connector takes the following parameters:
Connection name
Can be any name you want.
Active
If checked, then this connection will be active any time Gallium Data is running, meaning that the local port will be open and listening for requests. If you uncheck this (and then click Publish), then the connection is "commented out" -- it's as if it didn't exist, but you can still keep it around for later.
Type
The type of this connection, which is set at creation time and cannot be changed.
Server host
The name or address of the DNS server. This is the only required parameter.
Local address
Optional - the local address on which to listen for requests. This is useful only if your machine has more than one IP address. By default, the connection will listen on all local addresses.
Server port
Optional - the DNS port on the server (specified by the Server host parameter). This is almost always 53, the standard port for DNS.
Local port
Optional - the port on which to listen for requests. This is almost always 53, the standard port for DNS.
Default connection
The DNS connector allows you to have more than one connection, which is handy if you want to redirect requests easily (see the Redirecting requests page for details). There can only be one connection marked as the default connection in a project. All other DNS connections within the project must not be marked as Default connection. If there is only one connection in the project, the connection is considered to be the default connection and this flag is ignored.
Run on TCP
Whether to also run on TCP (in addition to UDP). This is normally desirable, since a DNS implementation is not complete without TCP. However, on many operating systems, opening a TCP port below 1025 requires superuser/admin privileges. If you do not have such access, you can turn this option off to avoid an error message on startup.
Packets
See the DNS packets page for details on the packets used with this connector.
Examples
There are a few examples showing typical code.
Request filters
The following request filters are available:
Response filters
The following response filters are available:
Duplex filters
The following duplex filters are available:
The DNS connector has a capability not available with the database connectors: it supports multiple connections. See the Redirecting requests page for details.