I am not a network expert but; a recent conversation has come up with a client asking to whitelist a range of ip's (let's say 250 odd for now) to transfer their data to us for processing. I should add here that we would provide an IP address to the client and we would whitelist their IP. It's not a 'here's our domain name to search for' deal.
Networks are uncomfortable with doing this as (I quote) it shreds the firewall. A member of security has justified saying no by saying DNS attacks might occur.
Can someone help enlighten me why whitelisting a large range or even just a range of ip's is bad and what the technical rationale is.
The DNS explanation seems irrelevant to what's actually occurring and IP whitelisting is a valid defence. What's the real issue or threat?
Is it just that we need to couple additional defences on a ngfw to offset this?
Anyone who's enlightened, please help me!