Tghis is a small website that is only up for the people who work here to use.
So now we go from singular...
That seems like kind of an odd thing to need for a web server ... How much unwanted traffic are you getting??
Chances are if it's that high, there is a reason for it that needs to be solved...not filtered.
not so much but it is annoying to see malwarebytes blocking a single ip as Malicious when it hits the sites over and over.
there are 100 sites total on one server
...To incredibly not
Which compels me to re-stress the initial question ... What problem are we trying to solve??
I can't fathom that you have 100 sites for employee use only. So I'm guessing that you have a single site on a shared host for the staff to use. And under the as described circumstances...that's very (very...) bad...for your companies domain name.
Here's why: Some Email black lists - most actually - work off the IP address given in the MX records only. However others - and by that I mean just enough to really screw you royally - work off of the IP address of the root domain name. So, if MBAM - a strictly client side filter - is flagging your employee site domain name, then Your Mail Server IS Black Listed
by those filters that block based on the reputation of the root domain name.
I'm currently going through this with one of our clients. Their Email - which is hosted by MS Exchange Online (e.g. Microsoft itself) - has a completely flawless reputation. Yet they consistently get blacklist rejections from certain domains that use the root domain based filtering, because their website is currently hosted on a shared host that has a hacked website that got the IP address they are all behind blacklisted. You don't need an IP filter...you need a new host.