Complete novice question about trunk ports

[ssenna641]

My friend gave me a cisco SF300-24 and I've started messing around with it. I don't have any previous experience besides google and pressing the question mark after every word on the switch so please reply very simply.

I'm trying to create a guest network and a personal network. I want both to connect to the internet but not each other. I heard that trunk ports allow more than one vlan on a port but I'm not sure how to set it up so I can connect my router to a trunk port.

My design is as follows:

port 1: router
port 3,4,5: vlan 2
port 6,7,8: vlan 3

I already know how to assign ports to vlans but trunk ports are harder to understand.

Thanks every. Not an urgent question. Just messing around.

[Peter Paluch · Accepted solution]

Hello,

To make the port 1 operate as a trunk port, the configuration would be simply

interface gi1
 switchport mode trunk
 switchport trunk allowed vlan add 2-3

However, to make use of this trunk, the router connected to port 1 must also understand trunking/VLAN tagging. Without this, it would be unable to understand incoming traffic. So my question is - what kind of router are you planning to use? Does it understand VLAN tagging? Not every SOHO router does, unfortunately.

Best regards,
Peter

[ssenna641]

Peter,

Thank you so much! Now I understand that the problem was with my router. I kept looking into more and more complex switch commands when I first tried that and it didn't work. Never thought to check the router for vlan capabilities.

[devils_advocate]

I believe the SF300-24 switch can be put in Layer 3 mode (default is layer 2) which means you will be able to use it to route between your Vlans. They do no support NAT however so your router would need to support static routes for this to work.