After domain mapping: browser request returns default apache page

The Problem
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I'm running a site locally: apache on my local dev host.

I've set up multisite and installed the Domain Mapping plugin.
My site is called 'multisite'. I have an entry in my hosts file for 'multisite2'.

I've created a network site called 'multisite2'.

However, when I attempt to navigate to it in my browser, I get the default apache page.

My installation process
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This is the first time I've set up multisite, so I'm probably doing something wrong.
I've closely followed the instructions in the codex for setting up a multisite installation for wordpress, including editing my wp-config.php.

What could I be doing wrong?

Thanks.