Combo ports have a combined input and output to and from the PHY chip. Only the optical port or the RJ-45 port can be used singly, but not at the same time. Whichever cable is connected first will have use of the port PHY. If the Ethernet port is used, you will configure it with 1/g48, if fiber port is used then configure is using 1/x48.  Yes, you are correct, a Trunk connection is what you want between the two stack. Commands on the PowerConnect will look similar to this. console> enable console# config console(config)# interface ethernet 1/g48 console(config-if)# switchport mode trunk console(config-if)# switchport trunk allowed vlan add 2,3,4,5 On the PowerConnect 62xx series switches, you must use General mode if you want to allow management traffic onto the switch over the PVID.  If you use Trunk mode, you will not have the default VLAN on those ports.  The ports will only allow tagged traffic. So if Trunk mode is not working out for you, then switch to General mode. Since the Cisco stack already has VLANs on it, we should make sure the PowerConnect has those same VLANs. Here is an example of creating a VLAN on the PowerConnect. console> enable console# config console(config)# vlan database console(config-vlan)# vlan 2 console(config-vlan)# exit console(config)# interface vlan 2 console(config-if)# name Marketing console(config-if)# end Something else you may need to do is place a static route to help the traffic back and forth from the stacks.  ip route {Network} {Wildcard Mask} {Next Hop-IP} console# config console(config)# ip route 172.16.0.0 255.255.0.0 10.0.0.2 console(config)# end Hope this info helps, Thanks.
Hi all, I need to extend the office LAN by connecting an existing CISCO 3750 stack to a new DELL 6248 stack. I intend to use the fibre/combo port In DELL 6248 to connect to CISCO uplink port. I want to use DELL port 48 but I saw there were 1/g48 and 1/xg48.  From memory, they are mutually exclusive. Q1.  Does it mean I will just configure 1/g48 and don't bother going into the config of 1/xg48? Q2.  To connect the 2 stacks together, should I just define both connecting ports as trunk port?  I have no experience in doing that.  FYI.  We are using VLANs in the CISCO stacks already and so the new DELL stacks need to know about it. Any help will be much appreciated! :emotion-5: 
Newbie connecting DELL 6248 stack to CISCO 3750 stack