Problems accessing our static IPs from our internal LAN

We have five Comcast static IPs here, of which only are currently in use for SSH, FTP, and HTTP/HTTPS.  Let's call them 111.222.333.111 through 111.222.333.115.  A sixth IP, 111.222.333.116, serves as the gateway for our LAN to get onto the Internet.

The problem is:

1.  Anyone from the outside can access the servers on our static IPs, easily, quickly, and with good throughput.

2.  Anyone on the internal LAN can access other servers on the Internet easily, quickly, and with good throughput.

3.  People on the internal LAN here can access the servers on our static IPs only with great difficulty, very slow operation, frequent timeouts and frequent disconnects.

It's not like it doesn't work at all, but the performance and reliability is completely unacceptable.  Again, outside access to our servers is near-perfect, internal access to the outside Internet is near-perfect, but internal access to our servers is unacceptable.

Since the servers are on dedicated static IPs, accessing them from our LAN should be exactly the same as accessing any other website on the Internet.

I have been on the phone at great length with Comcast customer service people and they have no idea what to do.  Most recently, this morning, I was on the phone for almost an hour with a customer service rep who had no clue what to do.  I finally asked to speak with someone who knew about this stuff, and he put me on "hold" and then disconnected me.  Yet another hour wasted with no result.

Two days ago a Comcast technician came out here and replaced the modem, ran some tests, and declared himself unable to diagnose the problem or guess what the solution might be.

I  have connected a workstation directly to the Comcast router, bypassing all of our internal network infrastructure, to rule out anything in our internal network that could account for any of this.  So, whatever the problem is, it's either in the Comcast router or out on the Comcast network.  In either case, it's Comcast's problem to fix.

I need to speak with someone at Comcast who knows about this stuff and can help me diagnose the problem.  I have tried several times to get past the customer service reps and get to someone who knows what's going on and have had no luck.

Someone please tell me if you have any ideas and also tell me how I can get in touch with someone who really knows enough to be able to help.

This is getting beyond frustrating.

Thanks...

Eric Poole

eric@rkt-tech.com