VLAN in cascade switch configuration

[jcaldazosa]

Hi everybody!

We are extending the network in the office, actually we have a Router/Firewall and a SG220-26 Switch (SWITCH 1) with VLANs working perfectly, we have two VLANS: VLAN 10 for DATA and VLAN 20 for VOICE, all of this in what I call AREA 1

Now we need to extend the network to 2 separated areas (AREA 2 and AREA 3), so we are using 2 SF300-24PP Switches (SWITCH 2 and SWITCH 3). Without using VLANS everything works fine, all the devices get DHCP, internet, etc. with the cascade configuration.

Now we need to configure the VLANs in AREAS 3 and 4, we need to have VLAN 10 and VLAN 20 in each area, I tried different configurations but I can´t get the VLANs passed to this areas.

Can someone give me any advice?

I attached a diagram to explain what we want to achieve. 

Thanks in advance!

[chris noon · Accepted solution]

You need to complete the following to get it working:

- Configure the VLANs 10 and 20 on switches 2 and 3.

- Configure the links between switch 1 and 2 and 1 and 3 as trunk ports.  Then allow VLANs 1, 10 and 20 through these trunk link.

- Assign the ports on switch 2 and 3 to the appropriate VLANs.

[jcaldazosa]

Hi Chris,

Thanks for your answer, that´s exactly what I did, but I think I´m missing something, I can´t make it work with the cascade conf. If I plug the router directly to any of the Switches, VLANS work properly, so it´s not VLAN conf what is missing.

Maybe the 'Tagged'/'Untagged' state is what I have wrong? How it has to be for the linking ports between SWITCHES?

Thanks in advance.  

[chris noon]

If the default VLAN is VLAN 1 as normal, then all other VLANs will have a tag, in this case VLANs 10 and 20.

The links between the switches cannot be access port, they must be trunk port in order to carry the tagged traffic from one switch to the other.  This might explain why the switches work when the router is plugged in directly to that specific switch but the other switches don't work.

Can you confirm you have trunk links between the switches?

[jcaldazosa]

Hi Chris,

Now it's working fine :) I changed the port to the router and didn't allow VLANs on it, silly me. After allowing it everything started to flow.

thanks a lot for your help!