Newer engineer here, Customer's 5505 firewall(that my company manages) is being pointed at as to blame, but I don't get why.

Hi Everyone.

I just started my job as a network/system engineer for a Full Solution Parking automation company, and I have a weird issue. We have a customer that's claiming our really old ASA 5505 firewall isn't allowing traffic, and I can't figure out why.

It'll disallow any connections to a few IP addresses in our credit card solution's public IP block, but allow connections to others in that same block. This is despite defining any-any acl rules on both the outside and inside interfaces.

Our firewall runs through someone else's ruckus switch and pretty much just goes through to the ISP. I've talked with the other company multiple times to confirm that my firewall is just hopping across a couple of switches.

I'm at a loss. Is my 5505 broken? Is there actually a firewall that no one knows about?

I'm super new to this, so if I'm missing some things let me know and I'll clarify.