How can I forward the internal Splunk logs of a Splunk deployment to another Splunk

That depends on the version. If you don't have any internal events being forwarded right now, you can enable forwarding of _internal events via the following:

Splunk 4.0 (and earlier):

You have to find the entry in inputs.conf that is responsible for monitoring your splunk internal log files and then add the mystical _TCP_ROUTING=* entry.

So add something like this to one of your `local/inputs.conf files:

[monitor://$SPLUNK_HOME/var/log/splunk]
_TCP_ROUTING = *

Note: Be aware that $SPLUNK_HOME/var/log/splunk/ log files can change based on platform. Also, in older version of splunk some of the log files were monitored individually, so you would have to add this for each [monitor:] entry.

Splunk 4.1

[tcpout]
forwardedindex.filter.disable = true

See the outputs.conf docs, specifically the section called Configuring which events are forwarded by index.

However, if you already have your _internal events forwarded and only want to forward your deployment log events, then you'll probably have to setup some transformers to re-route these events to a different index and then just forward that index. (That's just a guess. I hope, for your sake, it's not that complicated.... If so, we'll need some smarter people to step in.)

Hope this helps