Hello, I have two switches. Each one is in a different office joined by fiber. The schema is : N3024 Site 1 Port1 Vlan2 -- Fiber conversor - Fiber cable - Fiber conversor - N3024 Site 2 Port1 Vlan2 The fiber conversor is a Trendnet (ethernet-fiber 1Gb) I have created VLAN2 in both switches, in port 1. When I connect both ends : The port and the VLAN in the switch of Site 1 are UP. The port in the switch of Site 2 is UP : Operational Port Status Link Up Operational Port Speed 1000 Mbps but the VLAN2 in this port, is down ! Vlan1 Up 10.244.8.50 255.255.255.0 Manual Vlan2 Down 10.244.253.21 255.255.255.252 Manual If I connect port 1 to another local switch, the port become up immediately. I thought the problem was between the Dell switch and Trendnet in site 2, but in the other site (site 1), is the same situation and it work ! Thanks for your help !