NAT and Source Address

Say I want to block a website at If I am using NAT on my network how would I define that traffic? What would the source addres be?  Would I have to block with a firewall or access list before the traffic is NATed?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

on external router interface create a deny ip access list and on the internal router creat a loopback adapter and point all internal traffic to this address.

this will break communication in both directions.

If users are accessing it via DNS name (like for HTTP/s or FTP) then simply make a bogus A record and blackhole it...    Easier than messing with routers..

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.