Hello, I have two Cisco devices setup to talk to each other on trunk ports. The devices are a Cisco 3560 and a Cosco 2950. I setup fastethernet 0/1 port on both to be the trunk port between the two. First I set them up both to be dynamic desireable, and I tested by running a straight through network cable between the two. It worked just fine and my vlans and everything was functioning as it should. When I tried to move them to production I ran into an issue. the link between the two is via media converters/fiber. When I went to hook the two up, it did nothing. No ports would light up on either side. I tried making them both "trunk" ports (no dynamic) with dot1q encapsulation on the 3560. Still would not work. I also made sure both were no shutdown. When I pulled the connection (media converter) from the 3560 and placed it back into the old 2950 it was originally in (old 2950-no trunk port to new 2950-trunk port on fe0/1) now the ports lit up and turned green. I do need the trunk coming from the 3560 working though. I think I've narrowed down the issue to the 3560, but I'm not sure what it wrong. Can you help me get this working? Thanks ... View more

Hello, First time poster here. I am trying to solve an issue where I need two different networks/subnets communicating between my Juniper firewall and my Cisco 2950 switch. On the firewall I took two ports and split them up by assigning them seperate vlans (these are layer 3 ports). One vlan (port) is setup for network 10.1.1.x network, and the other is setup for 172.90.60.x. Communication is fine when I take a computer and setup a static IP in that range and connect it to the correct port on the firewall. The problem is that we have a media converter coming into the main room that has both networks running on it and I need to split these up from our Cisco switch. Previous to implementing our firewall this media converter was plugged into our Cisco switch (all default config) and both networks on it could talk fine out to the ISP switch and to the internet. I can plug in one of the vlan ports from the firewall into the Cisco switch and then plug in a test computer into a seperate port on the switch (correct static IP range on the computer) and it works fine. I can do the exact same thing for the other network and that also works fine. But when I try to plug in both ports from the firewall at the same time, it looks like it creates a loop and shuts the one port down. How can I get this to work so I can have them communicate without creating a loop? Is it possible? What would the best way be to go about it? I really hope this setup works because there is no other solution that I can think of to firewall the two networks off of that one media converter. Please see the attached PDF. That will show you exactly what I am trying to do. If you need me to provide any additional information or such, I will gladly do that. I really appreciate your expert advice and opinions. Thanks ... View more