We have a bastion server that we use to connect to multiple hosts, and our .ssh/config has grown to over a thousand lines (we have hundreds of hosts that we connect to). This is beginning to get a little unwieldy and I'd like to know if there is a way to break the .ssh/config file up into multiple files. Ideally, we'd specify somewhere that other files would be treated as an .ssh/config file, possibly like:

~/.ssh/config
  ~/.ssh/config_1
  ~/.ssh/config_2
  ~/.ssh/config_3
  ...

I have read the documentation on ssh/config, and I don't see that this is possible. But maybe someone else has had a similar issue and has found a solution.