[Repost] Limiting connections to CVS

[Gerard Samuel]

Reposting to list, as I was locked out of -questions over the weekend, and I 
don't know if I got any replies.
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I read somewhere that they were able to limit CVS pserver connections
to 4 a minute.
I would like to do something similar.
I currently have a firewall/nat box running 4.9-RELEASE-p1, using ipf.
The CVS server is behind the firewall/nat box running on 4.9-RELEASE-p1.

Thanks for any insight you may provide...