The Apache 2.4 new features page says: "The source address used for proxy requests is now configurable."
I can't find out how. The words "Source address" aren't mentioned on the 2.4 mod_proxy page....
Googling suggests ProxySourceAddress as a relevant parameter, but the discussion seems to be about a patch to 2.2 not what was done in 2.4...
So can someone point me at the documentation I may have missed?
ProxySourceAddress
is correct. See here.