Hi Guys,

I hope you can help me here, this problem really has me stumped.

We currently rent a rack in one of the Level3 datacentres in London.

In the top of our rack, our net connection is provided to us via a patch panel.

Now here's the problem:

If I use a straight-through cat5e cable to go from the patch panel into our WatchGuard firewall, I get a link light but nothing works.

If I use a cross-over cat5e cable, no link light, nothing works.

If I go via straight cable -> a switch -> straight cable -> firewall everything works fine!

I don't understand why I need to go through a switch, surely either a crossover or a straight cable should work.

I've tried using brand new cables, I've also tried setting the duplex on the firewall to manual, 100mbit full duplex incase it was auto-sensing it wrong! Not difference.

This leads me to another question:

At the moment I have our public internet going into our Dell 2726 gigabit switch then back out into our firewall external port. Because that is the only switch we have in our rack at the moment, we also use it for our server's internal network on a range. What are the implications of having public traffic and private traffic on the same switch? Is it a security risk? Are we going to be sending out private packets onto the public internet?

I'd really appreciate some help on this one!